Inverter Operating Temperatures

Rybren
Rybren Solar Expert Posts: 351 ✭✭
I've been doing a fair bit of looking around at lower-priced (<~$500) inverters (such as the Samlex 24V 1000W unit) for my new off-grid system. I noticed that many of the inverters have an operating temperature of 0 to ~ 40C. For folks who will install their systems in a heated house, it's no big deal. In my case, all of my electronics will be housed in a shed that is isolated from my cabins. Therefore, they will be exposed to ambient temperatures of -35C to +40C.

While we won't be spending a ton of time at the camp when the temp is below 0C, we will occasionally be there when it is cold. What sort of issues could I expect if I attempt to use the inverter when the temp is in the -10 to 0C range and the published operating temp is 0C+?

Thanks

Jerry

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures

    Sub freezing temps should not be a problem for the electronics per se, but could cause values to shift enough that it would operate outside of range. Of more concern is the condensation in damp conditions creating shorts between connection points.

    One the whole, the actual operating temp of the inverter will not be ambient because it will generate its own heat. I'd say ask the particular manufacturer of the likely consequences.
  • Rybren
    Rybren Solar Expert Posts: 351 ✭✭
    Re: Inverter Operating Temperatures

    Thanks for the thoughts. I am planning on firing off a few emails, but I do find that you guys usually give better advice :D
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures

    Ah, you mean like: "Buy an Outback and don't worry." :p
  • Rybren
    Rybren Solar Expert Posts: 351 ✭✭
    Re: Inverter Operating Temperatures

    That is good advice; however, I am somewhat constrained by my BCW (Beautiful and Charming Wife)
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures

    Most are constrained by their PBA (Pathetic Bank Account).
  • Rybren
    Rybren Solar Expert Posts: 351 ✭✭
    Re: Inverter Operating Temperatures

    Oops. Sorry, I thought that the PBA constraint was a given :blush:
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Inverter Operating Temperatures
    Sub freezing temps should not be a problem for the electronics per se, but could cause values to shift enough that it would operate outside of range.
    Can electrolytic capacitors freeze? Not sure about the SG of their electrolyte, but if they did, would their capacitance change? You betcha.
    A lot of electronics, for whatever reason, will have a range of storage temps that is a lot wider at both ends than their operating temps.
    SMA SB 3000, old BP panels.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures

    It's more like "cool down a resistor and then check its value".
    A temp that would freeze a cap would be miserable cold. Like Canada in Winter. Only we call them tuques up here. :p
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Inverter Operating Temperatures

    Never had a problem with my two Morningstar TS-300 inverters, nor my Xantrex 1800/12. all having operated in my outbuilding in winter temps. TS-300 is running this computer right now and it's minus 24C. Because of their specs re temperature, I expected problems, most likely due to capacitor values changing in the cold, but so far not a hitch at all, and it's going on 6 years for the two TS-300 inverters in continuous duty.
  • Rybren
    Rybren Solar Expert Posts: 351 ✭✭
    Re: Inverter Operating Temperatures

    Thanks for the real-world insights. I see that the TS-300 units are rated for -40C Operating Temp. The Prosine, on the other hand, is only rated for 0C.

    Jerry
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Inverter Operating Temperatures
    Rybren wrote: »
    Thanks for the real-world insights. I see that the TS-300 units are rated for -40C Operating Temp. The Prosine, on the other hand, is only rated for 0C.

    Jerry

    Yeah, I forgot about the TS-300 temp ratings, but yes I had really been concerned about problems with the Prosine due to cold. Took a chance on it anyway, and so far, after about 4 years, no probs at all. Example, this morning, temp is minus 22C (couple days ago it was minus 25C) and the Prosine as usual is doing just fine. So I'm not sure why they limit it to 0C in the specs. It almost scared me off the purchase. Hahaha
    BTW, last couple of years I didn't bother insulating my batteries, which are in a box in that same outside shed. Insulated them in past winters and they rarely if ever went below 0C temp, but this morning, after an extended period of very cold weather, they're the coldest since I got them. Minus 11C. So of course the charge controller, taking batt temp into consideration, has the absorb voltage pumped up to 15.25, At over 15.5 volts, the TS-300 inverters shut down on overvoltage. But that's rare, only happened once this winter, this morning actually when the MX-60 did a sweep that spiked the voltage for a moment. Easy to get them back though, just plug the toaster oven into the Prosine 1800/12 for a moment to drop the voltage to the point where the Morningstars kick back in. Hahaha
    Cheers
    Wayne & Bella
  • Rybren
    Rybren Solar Expert Posts: 351 ✭✭
    Re: Inverter Operating Temperatures

    Thanks again Wayne. It does make me feel a tad better. My camp will really only see 3-season usage, so the temp issue isn't huge. Although, on days like today when the ambient temp is in the -29C range, it would stink to have an inverter go down.

    It would be a much bigger player if I go with 24V for the new system. If I stuck with 12V, then I'd have lights without the inverter (my cabins are currently running off 12V LED and CFL lights)
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures

    Wayne;

    Is the Prosine on 24/7?
    Once an inverter is active its internal component temperature will not be ambient, even with no loads on it. That would help in most cases.

    Frankly I wouldn't expect trouble from cold for most inverters. Some of the cheap ones perhaps.
  • Photowhit
    Photowhit Solar Expert Posts: 6,001 ✭✭✭✭✭
    Re: Inverter Operating Temperatures

    Wayne is your Xantrex 1800 a Prosine? I thought you had done some testing on the new cheapy Xantrex 1800, though perhaps I have you confused with another regular here?

    I had mine down to -20c though it runs continuously.

    I wouldn't worry too much about humidity, I can't recall seeing a humidity rating for the prosines, it was originally built for marine use, the owners manual states;

    • Dry: do not allow water or other fluids to drip or splash
    on the ProsineInverter. Do not mount the inverter in an
    area subject to splashing or dripping water or bilge.

    Kinda 'no brainer' there...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter Operating Temperatures
    Photowhit wrote: »

    I wouldn't worry too much about humidity, I can't recall seeing a humidity rating for the prosines, it was originally built for marine use, the owners manual states;

    • Dry: do not allow water or other fluids to drip or splash
    on the ProsineInverter. Do not mount the inverter in an
    area subject to splashing or dripping water or bilge.

    Kinda 'no brainer' there...

    In this sue-happy age it's amazing it doesn't have a big red sticker on the case saying "do not operate under water" or some such.

    The problem with "no brainers" is the appallingly large number of people these days who have no brains. :p
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Inverter Operating Temperatures
    In this sue-happy age it's amazing it doesn't have a big red sticker on the case saying "do not operate under water" or some such.

    The problem with "no brainers" is the appallingly large number of people these days who have no brains. :p
    Hahaha OH SO TRUE!
    Photowhit wrote: »
    Wayne is your Xantrex 1800 a Prosine? I thought you had done some testing on the new cheapy Xantrex 1800, though perhaps I have you confused with another regular here?

    I had mine down to -20c though it runs continuously.
    It's the Xantres Prosine 1800 watt, 12 volt, (with transfer switch that I don't use). Purchased through Northern Arizona Wind and Sun Inc. Newer than I thought, just looking at the invoice, 18 Oct 2010. At that time $1107.00 before shipping and import duties to bring it into Canada.
    It's in standby mode 24/7 and fires up whenever the water pump needs to go, or any of the other large loads I may put to it, including washing machine, 1/2 (real) HP band saw, cut off saw, and assorted other tools, as well as the 120 VAC electric starter on the snow blower, and of course electric kitchen items etc. It actually starts the band saw quicker than grid power. That surprised me. The cut off saw is a bit slower to start though as it's a 13 amp motor and the start surge is far greater than that. Still the inverter handles them OK.
    It's also, or at least was available here in Canada from a marine supply outfit. Last Canadian $ price I had from them I think last year, was $ 1364.50 but there would be no import duties on top of that as it's already in Canada.
    A while back I had checked out a 1500 PSW offering by one of our Canadian automotive supply box stores, (is there more than one? lol) their own brand name, don't know who made it, but it was a piece of dog poop. Took it back. high idle draw to power all the fancy bells and whistles, at least they looked fancy to anyone who didn't know any better, and the surge capacity appeared to be even less than it's rated power. Hahahaha