Author Topic: MNB17-5 Surge Capacity and Load Regulation Capability?  (Read 340 times)

Basspig

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MNB17-5 Surge Capacity and Load Regulation Capability?
« on: August 04, 2020, 12:11:05 PM »
We use about 80kWH /day here. Have a recording studio, small movie theater with a medium venue projector and a 20,000 watt sound system and a full electronics lab on the first floor. 3 large air conditioners, electric range, stove, clothes dryer.

Our bill was averaging $740-ish per month for the past year. This month, Eversource forced through a 30% rate increase.

I've been looking at going off-grid for about a decade now, but several sticking points kept popping up.

The high cost of batteries and the safety issue of using Lithium batteries such as the used packs from Tesla automobiles that cost around $1100 for a 4.5kWH capacity. The other issue is that we'd need 150 or so 360W panels. I've cut down a lot of trees and now have an area of land about 60x20' that gets full sun from 7am to about noon.

Inverters seem like the cheapest component in the system. I've looked at some as cheap as 10-cents a watt. All of them seem to boast 3x surge capacity, one of the ones I was considering claimed 60kW surge for 20 seconds, 15kW continuous. That unit was priced at $3000. But I am concerned about reliability.

The thing that attracts me to the MNB-17 line is the fault tolerance/hot swappable nature of it.

I'm also very interested in finding out what such a system costs. I'm retired an on a fixed income, and can't afford these electricity bills any longer. Even if you use zero kwH, you're still paying a $200 'delivery charge' to Eversource, as my vacationing neighbors found out. An off-grid system is looking more attractive every day, especially if I can build one that will provide even 50kwH per day for under $15K.

Vic

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #1 on: August 04, 2020, 05:26:08 PM »
Just briefly;

You are considering a large system.

Off-grid power is often more expensive than Grid power,  with a few exceptions.
Usually electric utilities that provide grid power,  will not permit their customers to go off-grid,  without some significant compensation.   This is usually due to their concern for Stranded Costs,  that they have in the delivery infrastructure.

Cheap things are,  often,  just that  --  CHEAP.

If you have tiered rates,  where higher usage tiers cost more per kWh,   a smaller system that allows a larger percentage of usage to fall into lower cost tiers,  can help,  especially if such a system is grid-tied (no batteries).

Just some drive-by opinions.   Welcome to the Forum,   Good Luck!   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

boB

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #2 on: August 04, 2020, 06:23:18 PM »
Welcome to the forum !    So, you like bass ?  So do I !!

Sometimes you can find deals...  You would have to do most of the work yourself.   Some states may mandate that a professional install the solar array and even do the wiring.

That is, if it is to be inspected per NEC which is usually necessary to insure the house.

Batteries aren't cheap.   Getting surge isn't a big deal.  Some inverters are 2 to 3 times but some are almost zero surge.

The B-17 will be twice power for sure.   They have to be to be competitive these days.

50 to 80 kW-Hours per day is doable but I don't know if $15K is going to cut it.

If you are on grid now, I would say to slowly work your way up and use grid power as little as possible.

I am on grid and use about 30 kW-Hours per day which is kind of typical.  I guess I should change that.  I was able to get some PV for about 40 cents per watt but it is not up yet.  Will probably take that to my place in Sun City, AZ where the sun actually shines.

That brings up a question...  If you want to go solar too, do you have sun ?  Of course if you have a stream or some good water head, that works great if the permits can be done.   Or maybe even wind ?   It is hard to run yourself if you live in the city.

But it can be done if you have the space for the energy generation equipment, whatever it might be.



 
K7IQ

Basspig

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #3 on: August 07, 2020, 10:39:18 PM »
I'm seeing electric bills north of $740 monthly for the past year. I'm on a fixed income (retired) and can't do it anymore. I simply don't have the choice NOT to go off-grid. I can't keep up with the bills.

I'm not concerned about permits. I built my whole house in the woods 54 years ago with no permits.

What I am concerned with is what I can do with my financing limit. Paypal has $10K limit and I can use some savings that I've accumulated in cash over the past 60 years.

Technical factors: the source impedance of the inverter--the immunity to poor power factor loads that inject noise into the rest of the system. (A problem with generators). Right now we're on generator power due to one of the many extended outages after the many storms we get.

We have all electric range, oven, clothes dryer, air conditioning, etc. High capacity submersible well pump for firefighting (50 gals /min). And the biggie, me being an extreme audiophile, is my 20,000-watt sound system. A rack full of industrial pro amplifiers. Essentially, if you took the PA of a large rock concert venue and put it in your house. It taxes even our 200A utility service, dimming the lights up and down the road when pushing hard.

My goal is to do as much as I can with $15K.. 16 500 watt panels from Alibaba, a 15kW inverter, and ten Tesla 4500Wh lithium batteries in a concrete structure outside. I was looking at LifePo and similar, but 100Wh costs over $800 and I'd need $400,000 worth of batteries to fully replace grid power.

But at the moment, doing $30/day in gas for the genny, I'm anxious to get even a few kWh of panels and batteries up and running so that we can shut down this generator at night but still keep the fridge and a/c going.

boB

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #4 on: August 08, 2020, 02:08:15 AM »

WoW !   No WONDER your handle is "Bass Pig" !!   :)

Well, since we actually started in the amplifier and Hi-Fi and audio business, we definitely understand your need !

Way back around the time I was working for Bob Carver at Phase Linear, my outside front porch light would dim to the music and the bass.  I'm sure it was just poor wiring in that area of the house but it certainly made for an interesting effect !

The inverter is sort of a Class-D audio amplifier actually.   Just more involved.  But definitely a low output impedance.   High damping factor as they say in the audio world.

Too bad you couldn't change some of your heating equipment to gas operation since it is so much more efficient than electricity for that use.  Really what we need is a sub-woofer system that operates off natural gas !

But seriously, yes, you can certainly get electricity to do all of this for you.  I would be hesitant to come out and say that you could get the amount of kW-Hours you are looking for for $15K though.  Geesh...  One can spend 7 or $8K just on the inverter.   That leaves about the same for batteries and your PV.

BUT there may be hope as long as you are retired and thrifty and a technical geek you can do some or a lot of the work yourself.

OK, we will be talking more about this.   i am interested in what you can find on Alibaba for PV though.






K7IQ

mike90045

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #5 on: August 08, 2020, 03:03:49 AM »
If you are glitching the power from Hover Dam (the infinite Grid) you are not going to be happy dealing with batteries and inverters.  As stiff as the inverter output is, it's going to be tough to compete with a 60KVA pole pig fed from 13KV
I suggest you are going to have to split your house loads into 3 systems:
 
one to handle the heating tasks (electric oven and rang top, space heat) that can be accomplished with a mod sine inverter

one to service the audio gear (pure sine) and air conditioning

one to service the standard household appliances 

You could stack inverters, but will you tolerate them switching on / off with some of your major loads ?

This is going to be a strain for even a 48V bank, and you may need to engineer a higher voltage battery.
Whats the KWh usage to run your cooktop and air cond from 3 hr before sunset thru 3 hr  after sunrise ?? in winter ?

And actually, you need to consider a simple Grid Tie, because of your money limits and the cost of battery replacement

Choose some field space and install some ground mount arrays oriented to best service your solar usage plan . When you install solar, you get a new, confounding choice of ToU plans, intentionally  designed to maximize power co profits.
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

Vic

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #6 on: August 08, 2020, 03:36:44 PM »
Bass..,

Do you have tiered electric rates,   where increased usage is charged at a higher rate/kWh rate?

As mentioned before,   if you have such a rate structure,   a GT system can shave off some of the consumption in the highest tiers where the highest rates apply.

Large delivery charges really discourage conservation,   but,   conserve,  conserve   ...  CONSERVE  electric usage. This is the lowest cost way (generally),  to reduce your cost on electric bill.

I think,  as noted before,   that you ASSUME that an off-grid system will save you money.   That is seldom the case,   except for states like HI,   etc.

Please do not focus too much on CHEAP items for your system.   You usually get what you pay for,   and seldom get something that is not paid for.

Please join the Wind-Sun Forum.   It is a busy Forum  with reasonable,   well-informed folks,   that can help you decide a reasonable approach:

https://forum.solar-electric.com/

Conserve,   etc.   Good Luck,   and CONSERVE,    ...    Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Basspig

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #7 on: August 09, 2020, 04:54:31 PM »
boB, what a surprise to see someone here who knows my friend Bob! I used to have a lot of PL gear in the 1970s. Sold most of it in 2007 and reinvested in industrial amplifiers from QSC. I'm what you might call an extreme audiophile. Designed a lot of speaker systems since 1968. The setup I built in 1982 are pretty much the same today, except having updated the LF drivers and adding a lot more amplifier power. The main array is 112dB efficient below 40Hz. The system will hit 132dB with only 6 watts of amplifier power at 8' from the array. At times I've hit levels in excess of 150dB and it's like sitting in the front seat of an IASCA competition car audio system. There's just something about having your whole body shaking to a 32' organ pedal stop. :-)

Class D seems to be the way to go. That's like a 3-state PWM sinewave inverter. Low source impedance is important to keeping the power from getting dirtied up by even a single poor power factor load. The output of my Northstar 13kW genset is nice and clean until I turn on the Carver M500 in my recording studio. The glitches seen on the scope in the shop in another room are drastic.

Reliability is of course important. Resiliance to nasty spikes like motor start loads (well pump, 86 amperes LRA) and accidental shorts (yesterday I was starting repairs on a Carver Lightstar amp for a customer and the output transistors are shorted and customer says it pops the breaker) Fired it up to find out which channel was popping which breaker and when I found it, it nearly shut down the generator. Oh, yeah, we've been plunged into the early 1800s here in the northeast as our power company has barely any crews to repair lines after a widespread outage. Going on a week with no power and me tethering off my 4G phone!

Gas is out. I've seen too many homes blown up due to a leak. When I was working in Middletown at a radio station about a decade ago, a gas fired power plant was in the early phases of testing when it blew up. Damage for miles around from the shockwave! No gas for me.


mike90045: A split system would be great for redundancy, but would require significant rewiring of the panel. Presently, I'm feeding my genset into the panel with the main breaker off. I plan to run off grid with the genset replaced by a big inverter.

I've been told on the solar-electric forum that I would need $400,000 worth of batteries to accomplish my power needs! Tesla batteries are intriguing, but dangerous. They would have to be installed in a concrete bunker, just like my genset currently is, away from the house. But 4500Wh can be had for $1400. Ten of them would provide decent power.

When I'm not using the sound system, our power draw is a static 4kW. That's all the computers, lights, test equipment in my lab, and recording studio gear running.

On the A/C front, I've installed my first Mr. Cool DiY unit in April. I'm flabbergasted, because it seems to be giving me something for nothing in that it is cooling my studio very well for no more energy than a couple of light bulbs. I really found this out on generator power. My conventional LG air con really bogs down the generator when the compressor kicks on. But the mini split I installed doesn't affect the generator pitch or sound when it comes on, any more than if I turned on a 150W flood light. And it cools as well as the LG and does so silently. So I'm all for converting the rest of the house to these mini splits and that will eliminate the big load in summer.

We're so suffering under the high electric rates here that I told my wife to hang the laundry outdoors and stop using the dryer. That saved us $150 a month right there, but the very next month Eversource kicked in a whopping 30% rate increase, so that nulled out any savings. We'd be looking at $1000 electric bill if we used the dryer this month.

By far, my biggest load is dynamic and it's the sound system. The QSC amplifiers each can use 92 amperes of current at full output and I have multiples of these and other big amplifiers in my system. Fortunately, I rarely pop the 50A 240V breaker. I estimate the whole thing idles at around a kilowatt. I only turn it on for movies and once a month for loud listening sessions that last about an hour or less.

The other load is the well pump, which has a high surge current. When that kicks on, our UPS goes crazy when on generator power.

Grid tie is out of the question. I'm not dealing with permits and agencies. I'm doing this completely on my own, a little at a time. I built the whole house over many years, started in 1966, no permits, up here in the woods. Safety is a number one priority, as I can't get, nor afford homeowner's insurance, and it's worthless anyway, as my neighbors found out in 2018 when tornadoes destroyed their homes. I built for that, having lost my prior contractor built home to a tornado the year prior. It was also the Cold War, and I was planning to survive a nuclear attack. It turned out the robust construction was a huge benefit for my 150dB bass levels that I sometimes hit. Normally grid tie involves a lot of nasty contracts and the installers are sloppy and leave you with roof leaks. I just got done putting EPDM rubber down on my flat roof in 2017. And we sometimes get a lot of snow, which means I need panels that are at a slope so the snow slides off.

I cleared an area about 25x80' on the west side of my property. It gets full sun from 8am-noon. I was planning to start with 16 500W panels at $100 a piece from Alibaba, a 15kW split phase inverter, and a couple of Tesla batteries.

As far as I know, we have a flat residential rate here. I have a neighbor who shut off the main breaker when living overseas for long periods, and they still get a $200 electric bill. Highest rates in the nation, and they can't get the power back on after a tropical storm!

I know there's a lot of initial investment, but I see utility rates going nowhere but UP and rapidly so, while grid power is becoming less reliable every decade because of corporate greed and understaffing. So this latest outage has me thinking about getting SOMETHING up and running that will replace our genset and at least give us overnight power without the noise of the generator.

Is this rack mounted system on the market yet or available? Where can I get pricing?

boB

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #8 on: August 09, 2020, 05:50:50 PM »
Basspig, check out this short history...   There is a lot more to be added, especially regarding local pacific northwest audio companies and relations with the inverter industry up here but it's  a good start.

https://www.midnitesolar.com/pages/frontPage/nwHistory/history.php

K7IQ

boB

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #9 on: August 09, 2020, 06:29:03 PM »

The differences between large load changes with the grid and with an inverter with batteries is because an inverter, being solid state and limited power or current at the output voltage and the immense capability of the grid which really is a voltage source except for your home wiring resistance and the transformer at the pole of course.

An inverter, comparatively is a small source that is being regulated by feedback from its output and possibly, in addition, a bit of feed-forward regulation based on the battery voltage.

An inverter cannot respond in the exact same manner as the grid, which does not have to respond to anything, based on its relatively small load changes.

BUT, most of the industry tries to make regulation as fast as possible with load changes so that the voltage doesn't sag, droop or overshoot very much.

A typical tell-tale indication of poor regulation is dimming lights.  The less they dim and brighten with  abrupt changing of loads, the better.  At least, the less noticeable they dim-brighten, the better.

Some inverters are awful and some are great at this regulation.  We will always strive to be as great as possible.

K7IQ

Basspig

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #10 on: August 10, 2020, 05:02:23 PM »
I remember reading that history page, now that I see it again. You you folks also were involved with Xantrex as well as having roots at Phase-Linear.

I was pondering the design of a 3 state PWM inverter, employing about 100 HEXFETs and powered off two 180V banks of batteries. I figured eliminating all transformers was a step toward improved efficiency. But my main experience is with vacuum tube audio design and broadcast transmitters. In 2011, I retired from broadcast engineering and tower management and started Amplifier Experts.

You could say my life revolves around extreme audio. Keeping that big system operational long after electricity grid has gone the way of the dodo, is a major concern of mine. Myself and Dick Burwin are the two extreme audiophiles in the Northeast US.

I'm keeping an eye on battery tech. That is the big hurdle right now. Inverters are plentiful. Of course GOOD inverters are not so common. A good design with fault tolerance is important when that system is your ONLY source of power. That's what I like the modular approach to your designs. Batteries are a tricky component. The high density ones are a fire hazard (Tesla batteries, Lion), the safer batteries have short livespan and shallow discharge cycles and take huge space. Solid state batteries are on the horizon and seem to promise great gains in density. I was reading that 970kWH/liter was possible. That seems too good to be true, as right now, a LifePo4 reaches about 650WH/liter--less than 1/1000th the energy density. Has to be a misprint in the article.

I'm still shopping for solar panels. Alibaba has them for 18 cents/watt, for 500W panels, but I'm concerned about ordering from China. #1 they want bank transfer. #2, I don't know what tariff I'll be hit with. Domestic suppliers are over $1/watt for 320W panels. I'd need 48 panels and that is way beyond my finances as a retired person living on fixed income.

Back in May, I had seven large oak trees felled and now the western hillside of my property gets full sun from 8a-noon. I can put an array of panels there. That's about 70' from the house, so there's some copper expense, but that's pretty minor compared to the battery cost.

So is this product available for purchase yet? I've been following it for about 2 years now.

mike90045

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #11 on: August 10, 2020, 06:03:19 PM »
for some discount panels, that you would be ground mounting and not need a UL cert , check out the prices at SunElec
https://sunelec.com/
 They have some west coast warehouses, but still a drive for you.

500w panels are pretty tough to handle, big, heavy sails, likely best done with 2 people.  At least you are not going up on a roof.   Will they be vandal proof ?
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

boB

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #12 on: August 10, 2020, 06:55:11 PM »
I remember reading that history page, now that I see it again. You you folks also were involved with Xantrex as well as having roots at Phase-Linear.

I'm still shopping for solar panels. Alibaba has them for 18 cents/watt, for 500W panels, but I'm concerned about ordering from China. #1 they want bank transfer. #2, I don't know what tariff I'll be hit with. Domestic suppliers are over $1/watt for 320W panels. I'd need 48 panels and that is way beyond my finances as a retired person living on fixed income.

Back in May, I had seven large oak trees felled and now the western hillside of my property gets full sun from 8a-noon. I can put an array of panels there. That's about 70' from the house, so there's some copper expense, but that's pretty minor compared to the battery cost.

So is this product available for purchase yet? I've been following it for about 2 years now.

Yes, several companies were kind of related to those PL roots...  Spectro Acoustics, TAPCO, Audio-Control, Mackie Designs, Carver, Symetrix, Rane, Heart Interface, Trace Engineering, Xantrex (the takeover), Outback Power, MidNite Solar, Magnum Energy and probably another one or two I have forgotten to mention.

18 Cents per watt is an awful good price I can't argue with !  UNLESS there are additional tariffs to go along with that.

Too bad you can't get a bit of extra cash from your passion, somehow.  That would be the best of both worlds !

No, sorry the B17 is not quite ready yet.  I better get off of here and keep working on that !



K7IQ

Basspig

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Re: MNB17-5 Surge Capacity and Load Regulation Capability?
« Reply #13 on: August 11, 2020, 05:08:37 PM »
I was looking at these panels on alibaba:

https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=52806&SearchText=400+watt+solar+panel

They are as low as 18 cents/watt.

My initial plan was for 16 500W panels. That would provide enough power for up to 7 hours, given adequate storage capacity at my static load level.

The panels sold stateside are shockingly expensive. I could afford enough to power a small television set and not the whole house. No, not going on a roof. We are in a somewhat remote mountaintop wilderness with a few upscale homes recently built in the area. I'm slowly working to fence off my property, bringing in fill to raise up the front yard and then adding a fence in front to block traffic noise and conceal the house from street visibility.



boB: I still have a Spectro Acoustics 210R equalizer I'd bought in '77. Many of those names are familiar. Though some of it crosses into the broadcast market, where Bob Orban is pretty dominant. For decades, I lived among the many Optimod 8100A audio processors, which were ubiquitous at every FM station that I serviced.

This project of yours has been in the development stages for some time. I remember discovering it 2 or 3 years ago, if memory serves me. I hope it's ready for market while I'm still alive!