hello all
so i have finally finished installation of my second off grid system and i have been having problems with my DC SSR and my hot water dump load.
anyway I am running my dump directly off my battery bank 48V and using the AUX 2 waste not HI off 1 of my controllers to switch on/off.
problem is i keep burning up relays. i am using 75A 5-240V DC SSR and only putting 47Amps at 49.6V and once i turn on the aux the relay connects and never wants to disconnect after that.
now the relay always stays in the "on" configuration no matter if i have the 12V switch side connected or not.
i have 4 different relays all different brands all same results.
then i initially install the relay is "off" and there is no current flowing from the battery to the heating element. when i turn on aux 2 manually the relay turns "on" and current flows to the heating element, but, when i turn aux 2 off manually the relay does not turn off an current keeps on flowing into the heating element. after that happens the relay never turns back "off" after that.
I'm assuming i'm frying relays.
WbJr says the heating element was drawing 47A @ 49.6V today just after the sun went down with no PV input just straight draw from the heating element. battery SOC was 100%
does DC SSR need blocking diodes?
Generally, SSR's do need a heat sink. Even 50% load, a couple watts builds up without any sink.
Also, there are AC SSR's and DC models, are you sure you ordered DC models. They should have some sort of spec for latch and disconnect.
http://www.crydom.com/en/products/catalog/s_1.pdf specs on 1st page
These are AC only models, with DC control
http://www.allelectronics.com/item/srly-2425/25a-solid-state-relay/1.html
thank you for the reply
yes i am sure about the DC relay purchased here
http://www.ebay.com/itm/140534723852?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
also connected to a 100A heat sink
http://www.ebay.com/itm/271793449716?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
made sure the battery was connected to the (+) side of the relay and the load/heater element connected to the (-) side.
i also tried flotek 100A and same results. if i dont turn off the breaker and just leave it on it burns up the relay (smoke) within 2-5 mins of being on.
as mentioned earlier when the sun went down i turned on the heating element breaker just to see the load coming out of the battery and WbJR says 47A draw and CC reads 49.6V. battery 100% SOC and resting voltage 54V no loads on battery other than heating element.
burned/damaged 7 different relays today. don't know how to proceed.
my other system is running AC heating element directly off my inverter with AC SSR and works perfect for using excess power with waste not HI AUX 2.
was told to go the direct battery DC route and it would be better but it seems to be only producing problems. anyone running DC-DC ssr to heating element can give me any advise on how to hook it up properly?
as of right now my positive wire is coming off my (+) battery bus bar and passing through 2 breakers (one in my controller room and the other next to the water heater) then connected to the (+) load side of the DC SSR. the (-) load side of the DC ssr is connected directly to 1 heating element terminal, while the other heating element terminal is connected directly to my battery (-) busbar.
aux 2 connected to the switch side of the DC SSR.
with everything connected for the initial time no power passes through the relay and the heating element doesn't see any current. if i manually switch aux 1 on it activates the relay allowing current to flow to the heating element, but when i turn off aux 1 manually the current never stops flowing. after that point the SSR never goes back to the "disconnected" position it just always allows current to flow through. at this point i use circuit breaker as off switch as the relay is "stuck on".
not sure what i am doing wrong at this point. like i said WbJR is only seeing 47A draw out of the battery bank while the SSR is on.
tried to leave it on and see what happens and it fried internally (smoke and burnt plastic smell) within 3 mins of being on. the heat sink and relay are extremely hot at this time.
any advise would be lifesaving
here's the best DC output SSR (which really use s MOSFET)
http://www.crydom.com/en/products/panel-mount/perfect-fit/dc-output/
Also, when switching heavy DC loads, you can get a large inductive spike from the ON or OFF mode, and that can fry the innards.
Most PWM solar controllers use a FET or MOSFET as the switching device, it's a well established technology, and good factory prime parts should be fine.
You may want to get some 70V zeners and put them back-to back at the control AND load connections to snub any spikes.
Your 48V bank , when charging, can hit 64V, which is only a couple % away from the 70V limit on your relay,
Maybe the parts are miss marked and that's why they are on ebay
What exactly is the heating element you are using? I have never seen a 2500watt 48v element, the 47A at 49v is close to 2500watt.
If the SSR is getting hot and the heat sink too then the actual current draw may be significantly more, I assume you have the Wbjr between the -ve busbar and the battery and the SSR -ve is connected to the -ve busbar.
Take a look through some of the earlier posts here concerning water heating and DC SSRs.
Also google the Crydom D1D100 datasheet and see the wiring diagram that shows a diode used to supress inductive spikes, best to include one anyway even if your heating element is not a coil type design.
dgd
thanks again for the replies.
this is the heating element that is being used chose the 2000 watt 48V option.
http://mwands.com/store/dc-water-heating-elements/9-3-8-inch-dc-submersible-water-heating-element
the output/power readings that i provided was just what i got off the WbJR. with the batteries at 100% SOC (54V) and no loads running (0.0A on WbJR) i turned on the heating element and then wbJR says -46.9A and controller registers 49.6V wile the load is on.
still a newbie at this stuff so please try to be as layman as possible when explaining possible solutions/problems that you may see for my situation.
Yes Wbjr is hooked up with 1 side of shunt going directly to battery (-) negative terminal and other/opposite side of shunt on my Negative "bus bar". negative lead off heating element is going directly to negative "bus bar" with no circuit breakers in between just direct connection.
does the diode need to be across the load or can i connect it directly to the ssr? i was thinking of thins blocking diode any suggestions?
https://www.amazon.com/gp/product/B004FGPUE6/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A2TN19FHI2Z5KL
trying to spend as little money as possible to get this going. I though this ssr relay was just straight forward stuff. what could i be doing wrong?
Things you should know.
Ebay parts are often factory seconds or did not meet spec for their markings.
The SSR needs a properly sized heat sink with thermal grease. Period.End Quote.
A stud diode IS NOT a zener and will not protect against voltage spikes. Maybe research "flyback diodes" and "zener diodes". "Across the load" can be at the load or at the SSR, they are electrically the same. I would put it at the SSR myself.
More of those little details it is hard to pass along via a forum that can make or break a project.
I would suggest you source parts from someplace other than Ebay. My experience is the stuff from Ebay is quite often low grade junk Chinese knockoffs or seconds. Go to a reputable online parts source.
A lot of solid state components are more susceptible to over voltage than over current and even a bit of static from walking across a carpet can zap them if you don't properly ground yourself while handling them. The devil is in the details.
Best of luck.
Tom
Maybe you need to move up to something more substantial like a contactor. For all the relays you have burned up this probably is the same price.
Check with the EV parts place or the Gigavac - I am sure they will give you info on the correct product to do what you want it to .
http://www.evwest.com/catalog/product_info.php?cPath=2_13&products_id=407
http://evwest.com/support/gv200.pdf
Larry
Quote from: ClassicCrazy on January 21, 2017, 01:55:15 PM
Maybe you need to move up to something more substantial like a contactor. For all the relays you have burned up this probably is the same price.
Check with the EV parts place or the Gigavac - I am sure they will give you info on the correct product to do what you want it to .
http://www.evwest.com/catalog/product_info.php?cPath=2_13&products_id=407
http://evwest.com/support/gv200.pdf
Larry
Absolutely, if it is an on / off application and not PWM driven.
Tom
thanks everyone for all the input.
i did look into the crydom D1D100 and the price is $140 ish.
at that pricing should i just opt for a tristar TS60 and use it specifically as a diversion load controller PWM.
I do have a TS40 but the amperage that was being drawn from the element was a bit higher than that controller can handle, but a TS60 would be within amperage range?
what would be the better route?
a) purchase crydom D1D100 and use a diode to try to protect the relay. (problem is i'm not too sure of what kind of diode would be applicable in my situation blocking/flyback/zener?). this would be activated by waste not HI AUX 2 PWM and direct battery hookup
b) purchase tristar TS60 PWM CC and use it for diversion control and run it off the battery then to the heating element and hopefully it will work the same as having the SSR and AUX 2 waste not HI
i do have another system using a diversion load heating water for me but it is running AC directly off my inverter. been running great with no problems and harvests a lot of would be wasted energy throughout the day.
option c) run AC for this system also. instead of running DC off the battery bank i would need to source a bigger inverter and just run AC heating elements directly off the inverter.
don't know what to do......
Quote from: TomW on January 21, 2017, 10:33:08 AM
Things you should know.
Ebay parts are often factory seconds or did not meet spec for their markings.
The SSR needs a properly sized heat sink with thermal grease. Period.End Quote.
A stud diode IS NOT a zener and will not protect against voltage spikes. Maybe research "flyback diodes" and "zener diodes". "Across the load" can be at the load or at the SSR, they are electrically the same. I would put it at the SSR myself.
I would suggest you source parts from someplace other than Ebay. My experience is the stuff from Ebay is quite often low grade junk Chinese knockoffs or seconds. Go to a reputable online parts source.
Tom
thanks for the input. it sucks because the KYOTTO SSR's are technically rated for 5-220volts DC would my 48V battery bank be able to spike the voltage that high?
so basically the problem i have is that when the heavy DC load is turned on/off there are inductive voltage spikes and that is what is causing the relays to fry up?
not from overcurrent or reverse current?
why would the relay overheat so quickly when i leave the load ON. i did leave 1 relay on until it actually burned up and smoked only took about 2-3 mins. i am using a 100A heat sink with the relays and the heat sink ia also very hot to touch after 1 min of being on? why would this happen? it seems the SSR is producing the heat instead of the heating element.
is there any possibility that the AUX 2 12V source power is interfering with the 48V batery signal abd causing the relay to ground out and burn up?
is there anyone that has done this type of DC diversion water heating element using DC SSR at this high amperage?
need some practical advise from someone who has experience setting this up.
checked continuity with my gauge today and when i put the gauge to the beep/sound setting i get a beep when testing between my main + busbar and the negative (-) terminal on the AUX 2.
wondering if somehow when the CC sends the 12V signal to the SSR it could be grounding out to the negative wire that is coming off aux2?
tried for another 5 hours today to troubleshoot and no luck.
1 weird thing happend.
40A breaker has a trip current of 52Amps. had the heating elemet turned on with my clip on amp meter and meter was registering 46A and the breaker would trip after being on for a minute or 2. amps not near 52A.
There are different ways to setup the AUX contacts using jumper in the Classic - which way do you have yours set up ?
From Classic Manual
"Aux 1 and Aux 2 Graphs/Jumpers
Figure 3.0 shows the two Aux port terminals, with their respective
Polarities. These terminals are located at the bottom of the
Power board below the battery temperature jack. Use a mini
flat head screw driver to tighten the screws. The jumpers are
described in the section below.
In order to select operation of Aux 1 between relay contact or 12v output JP6 and JP8 need to be configured accordingly following the instructions provided in this section. (Set for dry contact by default)
When Aux 1 is used to supply 12v out, JP6 and JP8 have to be in the position shown in Diagram 2. The basic schematic of how this works is shown above. The 12v out is more like 14.5v. The maximum current from Aux 1 should not exceed 200mA. The Aux 1 output can be set to operate at either Active High (12V) or Active Low (0V) when the Aux 1 function condition is true. For more information see Configuring Auxiliary Input/Output on page 37."
okay I reread your original post and see you are using Aux 2 instead of 1
How do you have the AUX 2 set up for PWM ?
As others have said you probably need a larger heat sink, better quality relay, and the diode protection. And if you use one of those big Gigavac contactors it isn't going to burn up because it is made to switch on large loads and has built in protection for the coil.
Asking the questions you want to know to the Gigavac techs will probably be able to answer since that is their business.
There is a lot of discussion on Otherpower forums about using PWM for DC loads
http://www.fieldlines.com/index.php?topic=148314.0
Here is detailed discussion about using Classic PWM for hot water heating
http://www.fieldlines.com/index.php/topic,147132.0.html
Larry
You also probably want to reread this thread
http://kb1uas.com/mnsforum/index.php?topic=3352.0
You asked on this thread about if you need diodes and there were some suggested and also was suggested you call this relay vendor who could give you the support.
Larry
Can you get a meter and measure the actual resistance of that MWANDS heating element?
Dgd
Quote from: kauaisolarman on January 21, 2017, 08:52:38 PM
....checked continuity with my gauge today and when i put the gauge to the beep/sound setting i get a beep when testing between my main + busbar and the negative (-) terminal on the AUX 2......
Was the gear powered OFF everywhere when you did cont test ? Any stray voltage can disrupt the beep test.
And when you do cont testing, test it once, then swap the test leads around and test again, sometimes, polarized electronics (transistors, diodes, caps charging up from the meter power) can fool the test gear.
snubbing diodes. Beyond my skills to describe over the internet, how to install them, perhaps the SSR factory data sheets have simple outline suggestinons.
As to PWM switching, DC SSR's have limited frequency response to PCM signals. beyond a couple Hertz, I don't trust them.
Breakers - Depending on the style (thermal or magnetic) you get a very broad response (thermal) or precise response (magnetic) Breaker needs to be able to trip, don't oversize it too much, it has to carry the heater load 100%. Size the wire to be safe 1 gauge beyond the breaker trip point. 55A breaker, use 70A rated wire. Your desired amps will be at the high end of the float voltage.
AC load vs DC load. Add an inverter to the mix and use the inverter to drive the heater ? Maybe a signal relay can control the inverter remote On / Off ? Can the inverter start up under a stiff load ?
thanks
aux 2 waste not Hi being used for PWM to the switch side of the relay.
i didn't get to call solidstarerelaystore but i will on Monday. hopefully they can point me in the right direction and get my DC diversion load setup.
I was reading somewhere that if running more than 30A through a SSR it needs forced airflow over the heatsink to prevent overheating. can anyone confirm this.
as stated earlier i am running about 47Amps through the relay so maybe thats whats causing them to busn up within 1-2 mins.
seems like with that much heat to deal with over the long run DC water heating off the battery might not be the best way to approach this. with AC there are much lower amperage passing through the relay and way less heat prolong life of the components.
any thoughts
regarding heat. Forced Air - Baloney. The FETs in a 60a charge controller don't have forced air. A good DC SSR @ 0.4V drop, 50A, is only 20 watts. There are many 20w passive heatsinks. Desktop Computer CPU's are 100w roughly. big heatsink, quiet fan.
Or maybe a DC contactor from a golf cart is the way to go.
Quote from: mike90045 on January 22, 2017, 11:01:11 PM
Or maybe a DC contactor from a golf cart is the way to go.
Fine on a on / off output.
Not on a PWM output like he is using, for clarity to those that may not know it.
Quoteaux 2 waste not Hi being used for PWM to the switch side of the relay.[/unquote]
Exactly why forum advice needs to be carefully considered.
Just saying.
Tom
Quote from: TomW on January 23, 2017, 11:39:20 AM
Quote from: mike90045 on January 22, 2017, 11:01:11 PM
Or maybe a DC contactor from a golf cart is the way to go.
Fine on a on / off output.
Not on a PWM output like he is using, for clarity to those that may not know it.
Quoteaux 2 waste not Hi being used for PWM to the switch side of the relay.
Exactly why forum advice needs to be carefully considered.
Just saying.
Tom
thanks again everyone for the replies.
so the struggle continues. the heating element i am using is basically 2 1000W elements on 1 screw in rod that is paralleled together to get the 2K watts.
i have disconnected the parallel connection and now an only pulling 1000watts off the heating element.
same results as before, but, this time it will work for a little while longer before remaining in the shorted out "on" position.
measured the amps going through the emenent configured at 1K watts and i get 25Amps max.
I am using a 100Amp heatsink and it gets to 145 degrees F.
with only 25 amps going through the DC SSR it lasts a little longer than the 47A but still burns up eventually.
when i did my initial tests yesterday at 25A i could leave the relay on for up to 5 mins (thats when it got to 145F) and it would still turn off usning the aux 2 manual controls so i though that my problem was solved, but, today i had it set on "waste not HI" and it worked great for the first 15 mins of the absorb cycle (switching on and off properly keeping me at absorb) but then when i went back to check on it about 20 mins later it was stuck in the "on" position again.
going to call solidstaterelaystore and see if they can help.
any other suggestions?
anyone running a DC SSR with high amperage like me? how/what did you do to get your setup running properly.
thanks again everyone.
Use two 40 AMP bosch relays that are 12 Vdc contact , They can handle 80A in Parl-mode .Or Much larger ones that can handle huge amps with a small pull in / keep power.
VT
Ok so heres an update.
possible aux 2 12V (actually 15V for me) signal messing with load going to heating element.
so the other day with everything installed i used the aux 2 manual on/off to test if the SSR would actually turn on and off without burning up and staying in the on position. it did work, but, the relay and heat sink say temps of 145F! all this while running 24-25 Amps @ 50-54V to the heating element (1000-1400 watts roughly)
today i set it on waste not hi to see if it would hold up and it was working well for about 20 mins then the ssr got stuck in the "on" position again.
at this point i turned aux 2 to manual off position and was using my load DC circuit breaker to turn on/off the heating element.
anyway what i observed was that with AUX 2 in manual OFF (wires still connected to SSR) and heating element turned on (24A@53V) there was little to no heat produced by the SSR. left it on continuously for 20 mins and no heat produced.
before the relay got stuck in the "always on" position it would get extremely hot when using the aux 2 pwm 12V signal to activate the load, but after it got stuck in the shorted "always on" position with the same amount of power flowing to the heating element the relay was not producing any heat when not being activated by the aux 2 12V signal.
is there any way the aux 2 signal is causing a short in the relay and producing all the heat that i was seeing and toasting my relays?
i though that the signal 3-32V that activated the switch to turn on/off the load was totally separated from the load amperage and voltage inside the SSR?
seems like my problem is the load is grounding/shorting out through the relay to the 12V source side of the relay.
will do more testing tomorrow and post results.
called SSRstore today but no answer.
Can you draw up a schematic of your wiring and post it as it seems like your ssr is wired incorrectly and once energized by the charge controller it completes a short circuit. By drawing the circuit it would be less confusing ,also it would be helpful if you tell us were your are mesuring on the circuit for amps and voltages .precission in electrical makes a big difference (it works or it doesnt work ) doesnt make sense that there were many ssr burned up and different brands of ssr ,when they heat up that fast there either shorted out internal (defective) wired incorrectly,supper cheap relays, wrong relay used for load rating or voltage . Sounds like With all that heat the relay becomes your hot water heating element ( direct short ) like i said #1 we need to see your wiring schematic first to be capable of diagnosing properly.
Don
Are you switching the SSR with a PWM signal, or simply On - Off with a few seconds between switching ?
The SSR in full conduction is very low power. But if it's Switching Off-On-Off at a faster rate than 2Hz, you are operating it in pulsed mode where it can build up a lot of heat.
There are expensive SSR that can be rapidly switched, but you pay a lot extra for them
Quote from: mike90045 on January 27, 2017, 11:28:22 PM
Are you switching the SSR with a PWM signal, or simply On - Off with a few seconds between switching ?
The SSR in full conduction is very low power. But if it's Switching Off-On-Off at a faster rate than 2Hz, you are operating it in pulsed mode where it can build up a lot of heat.
There are expensive SSR that can be rapidly switched, but you pay a lot extra for them
i am using the same aux 2 PWM signal to switch another water heater element that works perfect just with AC instead of DC. (on a completely separate system)
i am using DC power on the current system i am talking about but the same type of SSR.
i will draw up a diagram and take some pics tomorrow
contacted SSRstore and got some advise about flyback diodes and some sort of capacitor clost to the SSR to clean up the power signal next to the relays.
will keep posting until everything is sorted out.
thanks for all the input.
Quote from: TomW on January 21, 2017, 02:56:48 PM
Quote from: ClassicCrazy on January 21, 2017, 01:55:15 PM
Maybe you need to move up to something more substantial like a contactor. For all the relays you have burned up this probably is the same price.
Check with the EV parts place or the Gigavac - I am sure they will give you info on the correct product to do what you want it to .
http://www.evwest.com/catalog/product_info.php?cPath=2_13&products_id=407
http://evwest.com/support/gv200.pdf
Larry
Absolutely, if it is an on / off application and not PWM driven.
Tom
what if i use the load side of the contactor for PWM (from a separate PWM diversions controller). and the 12V switch side just normal on/off application? (set aux 2 to manual on all the time and running 12V through thermostat then to contactor)
would that work with this type of contactor?
in other words if the contactor is in "on" position (allowing power to flow through) and i send a PWM load through the contactor (max 47Amps@57V) will it handle the PWM load and not need flyback diodes across the contactor load terminals?
just thinking of possible other options if the direct battery to SSR method doesn't pan out.
thanks again
Quotei am using the same aux 2 PWM signal to switch
I think if you contact the SSR Mfg, they will say you CANNOT use pulse mode as a trigger.
You can use DC on and off, but
not PWM, that will quickly violate the specs, and they will burn up.
Quote from: mike90045 on January 28, 2017, 03:27:44 PM
Quotei am using the same aux 2 PWM signal to switch
I think if you contact the SSR Mfg, they will say you CANNOT use pulse mode as a trigger.
You can use DC on and off, but not PWM, that will quickly violate the specs, and they will burn up.
thanks for the input. is that only for DC SSR? my AC SSR is working great using the same AUX 2 pwm as the trigger.
when i try with the DC SSR it just fails, but, i have tried to hook everything up and just turn on the 12V trigger manually (no PWM) to test if the relay would just turn on and off manually and it will only work until the SSR starts to overheat.
so basically i hook up the SSR and turn on the 12V switch manually (no PWM) and the load current flows through the SSR, but it starts to get extremely hot (NO PWM just constant on) until it cannot manually turn off anymore. so when i switch AUX 2 from manual on to manual off after the relay gets hot it will not turn off anymore just stays on all the time.
thats with a 100A heat sink connected to a KYOTTO 75A SSR with only 47A running through the element.
here is a diagram of how i have this wired
only thing different is instead of the 63A breakers i am actually running 40A breakers
(http://i1068.photobucket.com/albums/u447/rustansouza/solar/IMG_0203_zpswwuvx7fi.jpg?t=1485650645)
what wrong with that?
Hi Kauai..,
What is the exact part number of the DC SSR that you are using? Do you have a Link to the manufacturer's spec sheet?
What is the manufacturer of the Heat Sink used with the DC SSR, and any part number or spec sheet Link for that?
There are specifications for the SSR Temp Rise for various load currents. The heat sink will also have specs.
Normally, one would use a conductive grease or Silpad (tm) between the SSR and the heat sink. The heat sink should be mounted with the fins vertical, for maximum convection cooling. A fan may be necessary for adequate cooling of the heat sink.
Since you noted that manually operating the DC SSR without PWMing it, that it seemed to get excessively hot, it implies that either the heatsink is inadequate, excessively high ambient temperatures, improper heatsink mounting/orientation, or the DC SSR is perhaps defective, is a reject or a fake ... and so on.
There appears to be no clamp diode in your schematic, which could cause the SSR to fail due to excessive voltage when the SSR is turned off ... although in manual mode this may not have been the case.
In manual mode, when the SSR gets excessively hot, and cannot be turned off by the trigger input, has that DC SSR been damaged, and will never again work, or does it recover when allowed to cool to room temperature?
Major brand DC SSRs appear to not be made in 75, or 100 A models ... perhaps there is a reason for this.
Thanks, Vic
I found the specs for his SSR Vic
http://www.kyotto.com/eng_KG20.htm
Wonder what the exact PWM timing is set up for on his AUX.
Larry
Quote from: kauaisolarman on January 29, 2017, 07:45:38 PM
here is a diagram of how i have this wired
only thing different is instead of the 63A breakers i am actually running 40A breakers
(http://i1068.photobucket.com/albums/u447/rustansouza/solar/IMG_0203_zpswwuvx7fi.jpg?t=1485650645)
what wrong with that?
Everything !!!!!!!!!!!!!!
Load of heater 1
SSR is NOT to be used as a relay of just on off 2
do a real PRINT & USE ONLY WIRE SCHEMATICS , PIX OF STUFF i CAN'T SEE OR READ IS JUNK.
There needs to be a level ___________________ standard to ask .
I'm not guessing what was posted !!
DUH
VT
we will help , but Be precise rather than waste our time extracting !!!! DUH !!!
VT
What kind of thermostat is that in the AUX control line ? Is it a built in one on the water heater ?
Maybe you should try taking that out of line and see if your relay still heats up. Just thinking that if it is standard built in AC type it may not work right on DC. Not sure what is inside of those -- if they are just a simple switch or if they do some other stuff too with the AC.
I think his pictorial schematic is just fine - no problems reading it here.
Larry
Quote from: ClassicCrazy on January 30, 2017, 12:16:08 AM
I found the specs for his SSR Vic
http://www.kyotto.com/eng_KG20.htm
Wonder what the exact PWM timing is set up for on his AUX.
Larry
Hi Larry, Thanks ...
First, it is always very good to know EXACTLY what part we are talking about, so that part number would help make sure that we are speaking apples-to-apples.
YES, did find those "specs", which are horribly incomplete, and I hope are wrong -- the turn-off time is speced as "less (than) 1/2 AC Cycle" for this supposed DC SSR ... although I do not know what they mean by referring to it as a DC DC SSR.
We really need some specs on temperature rise verses current, and heatsink area, pulse duration verses current, any rep-rate limitations or curves, etc.
This DC SSR appears to be very inexpensive, and perhaps is not for serious users, a knock-off, reject, ... or ...
It is difficult to try to do Engineering problems without real Engineering specs on candidate parts, that are real, honest, and that specify data that is needed to design the product for a specific application, IMO.
FWIW, Thanks, Vic
thanks for the input.
@ CDN VT if the drawing is not up to your standards then look somewhere else. I don't remember pointing a gun at your head and requiring your input or help. you got nothing better to do than go online and make judgments about other peoples work? go watch some more porn.
Classiccrazy and others thanks for your actual input and help rather thank being a little B****.
as far as the thermostat it was the lower thermostat that came with the heater, but i understand that the lower water heater thermostat can be used in 12/24V applications as it is just a switch.
info here http://waterheatertimer.org/Convert-AC-water-heater-to-DC-water-heater.html
will try to remove the thermostat and see what happens.
thanks again for all that provided helpful input.
will keep giving updates until it is figured out. maybe someone else can benefit from the info in the future.
next step is to PWM the LOAD side off a Tristar ts60 and just use the SSR/contactor to run through the thermostat to turn off the tristar load when the water temps come up.
AC & DV SSR Are VERY different. AC power stops 60x a second, and allows an AC SSR to switch off ( electronically, you turn them ON, and the the AC turns them OFF 60x a sec, and then you turn them back on)
DC is a whole different matter, and your control signal "quenches" the power flow, at the expense of generating heat, the more often you turn them off (PWM) the hotter they get.
Try a test, using a switch and a battery to turn the SSR ON with your normal loading. I'll bet it runs much cooler and lasts a long time.
So, if you are wanting to do real mans work with real mans tools, you have to pay for them, as you have found, counterfeit junk on fleabay does not work. here are links to 2 real parts, each about $115 US
http://www.digikey.com/product-detail/en/crydom-co/D1D60/CC1683-ND/2060411
http://www.digikey.com/product-detail/en/crydom-co/D1D80/CC1684-ND/2060412
chose the one that fits your specs best.
Below the part, are the recommended accessories: copper terminal lug for hi amps, heat sink thermal pad, heatsink.....
You realize, you cannot place an 8ga wire under the screw terminal, it won't make proper contact, you must use a lug.
And read the stinking data sheet. If you don't understand how to wire this stuff up, you are doomed to repeat
repeat your mistakes over and over
MAX PWM Fq 800hz
Resistive loads only. Consider switching losses; at maximum frequency reduce to 75% output current.
Heat is your enemy - keep the part cool:
Heat sinking required, see derating curves.
Output wire 2 x 8 AWG
Thermal Resistance Junction to Case (Rjc) [°C/W] 0.34
It appears we have our very own "Sunking" here for any who know who I am referring to.
Quote from: kauaisolarman on January 30, 2017, 01:20:28 AM
@ CDN VT if the drawing is not up to your standards then look somewhere else. I don't remember pointing a gun at your head and requiring your input or help. you got nothing better to do than go online and make judgments about other peoples work? go watch some more porn.
Well, KSM, if this were any other forum your account would be frozen. Since it is a Manufacturer support website, you can get away with this.
Once.
Your hybrid parts picture and non standard drawing of the circuit interconnects is pretty useless for easy helping you so chill out with the attitude! There are accepted standards for depicting circuits and your crayon drawings do not qualify. This makes it much much harder to actually help.
Pretty easy to see you have absolutely no qualifications to do this yourself without the generosity of others.
I told you before you should probably get local professional help.
With this attitude, I suspect you rub everyone the wrong way as a matter of course and cannot get local help for that reason alone?
You have world class help here and they deserve a lot of respect for trying
Play nice.
Tom
I will respectfully disagree with you a bit on circuit drawings Tom.
There are schematics, ladder diagrams, pictorial ( which this one falls into ) and some often weird cryptic wiring diagrams I see on certain devices. They all have their own purpose and uses.
If this drawing accurately portrays the circuit it is as valuable as any others in my mind. It also includes information like distances, breaker sizes , SSR type, and wire sizes.
I have worked on a lot of devices, appliances, and electronics and it can take some time to basically do what his diagram does - isolate the one circuit and control that is being studied. Sure there could be other things that will come into play but other than detailed photo's or an onsite visit it would be difficult to take it all in.
We all learn from our mistakes - at least I have . The next job I do is usually better than the previous . And let me tell you I have made some real wiring tangles in the beginnings - especially before internet when I could publicly post up those messes for critique .
Larry
Quote from: mike90045 on January 30, 2017, 02:11:12 AM
AC & DV SSR Are VERY different. AC power stops 60x a second, and allows an AC SSR to switch off ( electronically, you turn them ON, and the the AC turns them OFF 60x a sec, and then you turn them back on)
DC is a whole different matter, and your control signal "quenches" the power flow, at the expense of generating heat, the more often you turn them off (PWM) the hotter they get.
........
MAX PWM Fq 800hz
Resistive loads only. Consider switching losses; at maximum frequency reduce to 75% output current.
Heat is your enemy - keep the part cool:
Heat sinking required, see derating curves.
Output wire 2 x 8 AWG
Thermal Resistance Junction to Case (Rjc) [°C/W] 0.34
Mike - You make a lot of good points that need to be taken into consideration ! There is more engineering in some of those devices than meets the eye sometimes !
Larry
Quote from: ClassicCrazy on January 30, 2017, 12:48:19 PM
I will respectfully disagree with you a bit on circuit drawings Tom ...
Larry
Not to try to argue with anyone, but, I do totally agree with Larry.
That diagram was/is perfectly adequate for the purpose that it was trying to serve ... AND, it DOES have the part number of the DC SSR (which I had erroneously asked for).
One additional comment. Kauai.., it is good that you are not using the thermostatic switch in the DC supply side of the feed to the water heater element. Over time, you could possibly find that this switch function may become intermittent, as those switch contacts are designed to handle fairly large AC current, and the action of this current can help keep these contacts clean.
For a "dry circuit", there is essentially no current flow, and therefore the contacts can get dirt, dust or a film which can cause the contact resistance to become so high, that this switch could fail to pass enough current for the switch to do its job.
Many times, switch and relay contacts which are designed for very low current circuits are Flashed or plated with Gold or similar, essentially inert metal, to allow lower contact resistance at continued low current operation.
And so on ... Vic
@ Mike, Larry, and VIc
thank you very muck for your input and helpful information.
someone can definitely learn something from what you put online.
@ TomW, sorry i don't mean to slander or degrade anyone online, but if they (CDN-VT) send it my way i may just return to sender. hopefully he got a good reprimanding also for his useless post that did nothing but insult me and my work. just sayin ;)
anyway back to subject
I will definitely try the better quality SSR and stay away from the cheapo stuff.
only reason for not going with crydom to start with was i read some bad reviews online and Kyotto was noting but positive.
but lesson learned.
i have been in contact with SSRstore and they are setting me up with 1 of their SSR's and some protection diodes for it.
as far as the wire i am using 6 awg thhn and they terminate with a lug that goes on the screw terminals of the SSR.
not sure what PWM freq aux 2 sends from the classic.
an update:
since i burned all my SSR's and waiting for more "quality" ones to come in i have been playing with my tristar (PWM) CC and using it as a diversion controller.
it works good. diverts my excess power and heats my tanks to 140 degrees. only problem is when the tank gets to temp i have to manually turn off the breaker to stop the diversion.
i was thinking instead of PWM on the switch side of the DC SSR i would instead keep the tristar sending the PWM diversion load and just hook the switch side to always on and run through the thermostat so that when the thermostat reaches temp it can turn off the 12V switch signal and cut off the PWM diversion that is comming in off the tristar.
this way the SSR is always in the "on" position and the load side will see the PWM and the SSR would only be switched to "off" when the water temps are up to 140 degrees.
could the DC SSR handle the PWM through the load side if it is always in the "on" position? or is it because i am sending a PWM DC current i would still need the flyback diodes across the load terminals of the SSR?
thanks again if your contributing helpful information. i'm sure i am not the only one that will benefit from this information being out here.
Quote from: TomW on January 30, 2017, 12:01:29 PM
Quote from: kauaisolarman on January 30, 2017, 01:20:28 AM
@ CDN VT if the drawing is not up to your standards then look somewhere else. I don't remember pointing a gun at your head and requiring your input or help. you got nothing better to do than go online and make judgments about other peoples work? go watch some more porn.
With this attitude, I suspect you rub everyone the wrong way as a matter of course and cannot get local help for that reason alone?
Tom
wow, so someone bashes me online and then i am the one with the bad attitude? not sure how you came to this conclusion?
did you not read the post he sent my way? how is that considered world class help? if i helped people like that i seriously doubt it would be considered world class.
my opinion on respect is that if you want it you should learn to give it.
i have never started a post or discussion on this forum that put anyone down or disrespected what they said but i have been made fun of more than once for not being up to the "standard" of the people on this forum.
respectful VIP treatment for sure.
not trying to be rude or anything. just returning to sender.
have a nice day
rus
Quote from: ClassicCrazy on January 30, 2017, 12:48:19 PM
I will respectfully disagree with you a bit on circuit drawings Tom.
There are schematics, ladder diagrams, pictorial ( which this one falls into ) and some often weird cryptic wiring diagrams I see on certain devices. They all have their own purpose and uses.
If this drawing accurately portrays the circuit it is as valuable as any others in my mind. It also includes information like distances, breaker sizes , SSR type, and wire sizes.
I have worked on a lot of devices, appliances, and electronics and it can take some time to basically do what his diagram does - isolate the one circuit and control that is being studied. Sure there could be other things that will come into play but other than detailed photo's or an onsite visit it would be difficult to take it all in.
We all learn from our mistakes - at least I have . The next job I do is usually better than the previous . And let me tell you I have made some real wiring tangles in the beginnings - especially before internet when I could publicly post up those messes for critique .
Larry
thank you sir. all i can do is try my best and always strive to do a better job than the last. we all are learning at some point.
thanks again for all the helpful input and comments to my questions.
Kauaisolarman,
All of the info you need on wiring a water heating element, SSR, SSR rating, spike supressing diode, diode type etc has been well covered in previous threads on this forum.
I'd recommend you search and study those threads.
Otherwise, with respect, you are driving a never ending thread, asking questions without providing the details of your system, the exact devices, exact wiring and photos to show everything.
This means people are answering as best they can then you immediately ask another question and it goes on ad nauseum.
You appear to be behaving as a troll, when you get criticising answers you fall back on the excuse of being a beginner and trying to learn, solution go buy a book, hire someone who knows what they are doing, find a course at your local college.
I hope you get your RE system sorted out
dgd
yeah.....
i though the forum was for that..
asking questions and getting input and answers.
if the forum was only for fully educated folk that read all the books and have all the knowledge that needs to be had then why even have the discussion in the first place.
Funny how you people are quick to criticize someone that asks a "wrong" question and the act as if you know it all.
sucks because when i started posting here i thought the members would be a little more courteous and mature about dealing with newbies and people that were not as knowledgeable as they were on the subject matter.
I guess this is like any other forum with know it all people that always reply the same way."use the search"
for your information i have read through all the threads on the forum discussing using a water heater do divert excess power i have also read other forums as people have pointed me in that direction. thats how i learned to wire up what i have in the first place. problem is the information is obviously not complete as it is clearly not working the way the forum and other posts described that it would.
the problem/issue that i am having is specific to my system and setup thats why i brought up the questions in the first place.
WHY ARE YOU EVEN POSTING IF YOU ARE NOT HELPING ME ANSWER MY QUESTION AND HELP SOLVE MY ISSUE. WHY DO YOU FEEL THE NEED TO TELL ME WHATS ON YOUR MIND AND HOW YOU THINK I SHOULD POST THINGS? ARE YOU A TROLL?
sorry i am not a internet forum guru or specialist so i dont even know what a "troll" is.
all i am doing is asking genuine questions and hoping for genuine help.
makes me hope that if one day you want to learn to do something that i know how to do and you have a question for me i cant wait to call you a "troll" and tell you go read some books because all the information to what you are looking for is already out there.
this is my last post and i wish good luck to anyone else that wants to use this forum for any help.
all you get is criticizm and sarcasm. from these "know it all" superusers that have read all the forum posts and know all the forum answers.
i though the midnite solar forum was for midnite solar customers that needed help with their products. i have purchased 4 midnite classic charge controllers and over $2000 in midnite solar accessories and this is how i get treated?
great stuff
better look somewhere else. or "read a book, hire a professional, take some college courses"
maybe i can get better help from somewhere else anyway.
this forum sucks
kauaisolarman
You have been given a lot of help - there are 4 pages on this thread alone.
I am no expert with SSR but have spent a bit of time looking stuff up to answer your questions - and as DGD has said I have read and learned a lot about SSR in past discussions on this forum ( some are your own that were answered in the past ).
If I summarized the suggestions to fix your problem that has already been given in this post is -
Spend the $$ needed to get a good quality SSR that can handle PWM, heatsink it properly, and install the correct diodes.
You said you have contacted an SSR manufacturer and they will provide you all the parts that are needed to do the control you want to and they will back up their product.
I think you have done some good research and work in putting together your system from what you say , but I also see how it is frustrating for the experienced installer on here since it is so difficult to provide detailed answers without an onsite visit or detailed photo's of the whole system wiring. Everyone could talk and suggest till they were blue in the face but a person there might immediately see - oh look at that - there is the problem.
So everyone wants you to find a solution and report back when you get the proper parts to do the job correctly .
These forums are volunteers giving advice and not employees of Midnite ( sometimes they pop in ) . So don't associate criticism of your posts here with Midnite the company . It does seem like your last post you want to bite the hand that feeds you !
Larry