Internal Temperatures

[NCPW]

Is there any info on what internal temps are acceptable for MidNite Classic 150
Currently 35 amps output 48v system
Temperature:
FET: 52.5°C     PCB: 52.4°C
BAT: 28.0°C

What would the expected temps be if we were @ 80 amps ?

[zoneblue]

That sounds about normal. It does depend on your ambient, makes quite a bit of difference. Then basically they always run 40+C, as at high throughput the controller is alot more efficient than when running at low throughput. So basically the thing will always keep your hands nice and warm.

[boB]

Yes, those temperature readings are pretty normal for that power.

The PCB temperature sensor should probably be moved some day because it is kind
of close to a component that dissipates more than others I think...  Not the best
representation of control board PCB temperature really.

[robertp]

Hi, I have just commissioned my new Classic 150. On the first day (a few days ago, during a sunny spell) it registered the voltage coming in from the PV panels, but there was nothing going into the batteries (nil Amp and W). On my next attempt today all seems to be working fine with 160 W coming in on a dull day. Let's hope it powers up to potential when the sun comes out.

My question relates to the internal temperatures.  On both occasions the fan whirs constantly but the Classic is obviously not  working hard (see above) and we're in the middle of winter (NZ) - ambient temperature in the shed where the Classic lives is 5 Deg C. Does the classic not have a thermostat that will tell the fan only to kick in when the internal temp get too hot?

[tecnodave]

Robertp,

The fans in the Classic are thermostatically controlled. The main fans come on at approx 48 c. The turbo fan on top comes on at some higher temp.  The Classic works harder and generates more heat at lower power levels as they are more efficient at higher power levels.

td

[robertp]

Hi Technodave,

Thanks for your reply. I imagine I should be able to feel the heat if I put my hand on the Classic? She's stone cold, as is everything else at the moment, yet the fans goes non-stop, night and day, everyday. Batteries are getting slowly up despite dull weather and reading 26.8V.

Rob

[zoneblue]

Something doesnt sound right mate. Its 0930hrs here in Taranaki, ambient in the shed is about 15C, classic barely awake (and grey) producing 165W, PCB 39.3C, controller exterior with IR thermo measures 32C, fans silent. Fans only come on a few minutes a day here.

[robertp]

Hi Zoneblue,

Thanks for your reply. I had a look at your excellent website. Nice job: both your installation and the website. I wish I'd read the part about commissioning the system earlier…  Still, no harm done. You write about grounding the neutral to earth in the AC fuse box, but I don't see this from the photo you show. Can you explain? I haven't done so, and I now realise it could explain why the inverter says 'abnormal AC'.

BTW, the Classic has gone from Bulk to Float during the mostly sunny day we've had here on the West Coast, but the fan still goes unwaveringly 24/7. Any ideas?

Cheers,

Rob

[Halfcrazy]

Hi Zoneblue,

Thanks for your reply. I had a look at your excellent website. Nice job: both your installation and the website. I wish I'd read the part about commissioning the system earlier…  Still, no harm done. You write about grounding the neutral to earth in the AC fuse box, but I don't see this from the photo you show. Can you explain? I haven't done so, and I now realise it could explain why the inverter says 'abnormal AC'.

BTW, the Classic has gone from Bulk to Float during the mostly sunny day we've had here on the West Coast, but the fan still goes unwaveringly 24/7. Any ideas?

Cheers,

Rob

I am coming into this late but the fans should not run 24/7 so try this:

Go to the Temps menu and report back FET temp?
Take the front cover off with it running and see if the fans stop. we do see the fan wires get pinched in the cover from time to time and there was a short period where there was a wire that could touch the cover on the circuit board to cause this.

So let me know if the fans stop when you remove the cover and if the fan wires looked pinched

Ryan

[zoneblue]

Oh yeah Ryans onto it. There are three fans in the classic. Two in the lower area, are fairly quiet. They come on first, There is also a fan in the top right plastic 'turbo' housing. It is a louder/faster fan. Put you ear to it and determine which fan is running.

The turbo red and black wire pair is clearly visible at the top right of the case. Inspect it for damage.

[zoneblue]

You write about grounding the neutral to earth in the AC fuse box, but I don't see this from the photo you show. Can you explain?

Bear in mind that what follows applies for NZ only. NZ uses the MEN (multiple earth) system.

The point of the earth-neutral bond is to reduce electric shock risk, should an appliance become faulty. Having only one live wire means that should that live wire short to a metal outer case of an appliance then ac breaker/fuse will blow and the danger removed. RCDs are now also compulsory since 2003. The point of them is to detect an imbalance in current flowing out through the phase, and not returning via the neutral. See wiring diagram below. Hence the bond must go before the RCD not after. Thats important.

Bear in mind that it is illegal in this country, and most others that people wire their own distribution boards. The purpose of that law is to try to prevent people killing themselves and others. Energy from an inverter is no less or more dangerous then energy from the grid. It is likely that in the event of a death, people who have wired their own AC distribution boards could be held responsible in fairly serious ways.

However I saw a pertinent quote yesterday, that said something to the effect of the the purpose of rules is to make sure you understand the point of them... before you break them. As people seem determined to wire their own boards, hopefully the diagram below will help.  Also attached is a typcial NZ DB baord. Metal boards have largely been phased out. You can see the neutral bond  highlighted.

See also:
- http://www.electrolesk.com/Work/Wiring%20of%20Single%20Phase%20Distribution%20Board.htm (general)
- http://www.stewartsgroup.co.nz/19/news/28.html (NZ)
- http://updates.clipsal.com/ClipsalOnline/Files/Brochures/W0000433.pdf
- http://electrical.theiet.org/wiring-matters/19/understand-rcds.cfm?type=pdf

Lastly, you need to be sure that your inverter and/or generator doesnt have its own (half baked) internal bond. Those can be found in some gear that isnt really intended for permanent household wiring.

[robertp]

Thanks Zoneblue for your concise reply and links. I have a similar setup to the one illustrated (RCD, MCB's) but have not linked the earth and neutral bar as you have circled in your picture. I will prepare the wiring to the best of my ability, then get the system checked by a sparky.

Also Thanks Ryan and Zoneblue for the tips regarding the fan. I will head out and have a look inside the Classic and get a FET temp reading off the Temps menu. It sounds like the turbo fan keeps going. Back soon…

Rob

[mahendra]

yes yes we all know the overwhelming feeling a person experience when the had experienced real customer service. i know becasue i have experienced it right here at midnite solar too.

[zoneblue]

This is a good solution. Most provinces will contain at least one solar friendly sparky, who will sign off your board for a couple hours.

Thanks Zoneblue for your concise reply and links. I have a similar setup to the one illustrated (RCD, MCB's) but have not linked the earth and neutral bar as you have circled in your picture. I will prepare the wiring to the best of my ability, then get the system checked by a sparky.

Also Thanks Ryan and Zoneblue for the tips regarding the fan. I will head out and have a look inside the Classic and get a FET temp reading off the Temps menu. It sounds like the turbo fan keeps going. Back soon…

Rob

[robertp]

I haven't found my clued-on friendly local sparky yet, but everything now appears to be working fine. I'll keep looking…

The problem with the fan was solved when I was undoing the cover screws of the Classic. I checked the cable; seemed fine, carefully replaced it but the same problem recurred when tightening the screws. I've backed off the tension and the fan is now working as it should.