mid-power inverter choices

mike95490 · August 2014

Adding a new structure to the compound, and it will have it's own Fridge. I'm planning on a 24V based system, to power lights, laptop and an energy star fridge. I'm looking at 3 inverters, in the 600w range, that I think would be able to start a fridge, but wondering about feedback on how to chose between them:

Samlex PST 600 Watt http://www.solar-electric.com/inverters-controllers-accessories/inverters/sasiwain1/samlex-pst-series-pure-sine-wave-inverters/samlex-pure-sine-wave-inverter-pst-600-24.html

Samlex SA 1,000 Watt http://www.solar-electric.com/inverters-controllers-accessories/inverters/sasiwain1/samlex-sa-series-pure-sine-wave-inverters/sa1wa24vosiw.html

Exeltech XP600 24-volt 600 watt http://www.solar-electric.com/inverters-controllers-accessories/inverters/exsiwain/xp-600-24.html

Any feedback on sleep mode, or if the remote control is useful ? The inverter will be sheltered, but outside the house envelope and will see 100F daytime highs, and 20F winter lows. Some look like they have integral outlets, can they all be wired to to a conventional single phase panel.

I plan to use a Midnight Classic 150, on a 60V 800W PV array, and use it's output amps limit to protect batteries in the summer. (I have to size for winter usage.)

Then there is the backup charger. Is there an efficient 24V integrated inverter/charger that can run off a generator, or am I better off with an Iota charger ?

Cariboocoot · August 2014

Re: mid-power inverter choices

Some observations.

The Samlex PST 600 is not likely to start any refrigerator. The SA 1000 should.

The Exeltech 600 might start one, depending on what other loads are on at the same time.

The SA 1000 uses more power than the Exeltech 600 but the latter doesn't have a sleep mode (that I can see) and the SA does, meaning over-all it is likely to use less power.

Buying a stand-alone charger to go with one of these is cheaper than any quality sine wave inverter-charger I know of. When they put that charger in they tend to go up in power (2kW or more) to make it worthwhile, and hence they go up in price. A lot.

None of these are designed to be hard wired, but that doesn't mean it's impossible.

BB. · August 2014

Re: mid-power inverter choices

Our host has generally recommended 1,200 to 1,500 Watt minimum AC inverters for refrigerator usage.

Question--Is the refrigerator going to be a frost free (internal defrost heaters) or a non-frost free (or freezer converted with a refrigerator temperature control)?

In general, a frost free refrigerator has a ~12 hour timer... Approximately 1 hour or so of "defrosting" every 12 hour cycle. And (Niel?) found that running a frost free refrigerator without the heater would start icing up the evaporator in ~24 hours.

The cheap frost free refrigerator have a mechanical timer and it "May" work OK on an inverter with "search mode"--But it stretches the 12 hour cycle out by the compressor duty cycle (~50% duty cycle, 24 hour defrost cycle). Also--When the defrost cycle is running, your heater will probably turn on and off--Which will probably cause the 6 watt search mode to cycle on and off too--Sort of a mess trying to mix frost free + search mode inverter.

Some refrigerators use an electronic timer--Which as been reported as starting a new defrost cycle every time AC power is restored. Not good for a defrosting cycle.

Probably just easier to just get a larger solar panel array and battery bank to allow the AC inverter to run 24 hours per day (assuming 10 Watt Tare losses and 4 hours per day minimum sun):

10 Watt "tare losses" * 24 hours = 240 Watt*Hours
240 Watt*Hours * 1/0.52 system eff * 1/4 hours minimum sun (~9 months of year without generator backup) = 115 Watt larger array (guessing)
240 WH * 1/24 volt battery bank * 2 days no sun * 1/0.50 maximum discharge = 40 AH @ 24 volt larger battery bank

-Bill

Blackcherry04 · August 2014

Re: mid-power inverter choices

I bought one of these to fill a gap on a 24V bank and run a full size refrigerator on. It even has a 30 amp built in charge controller that I haven't used and a small AC charger and AC transfer switch.

The 48 V is a heck of a deal @ $500

http://www.powergatellc.com/mean-well-tn-1500-dc-ac-inverter.html

vtmaps · August 2014

Re: mid-power inverter choices

mike95490 wrote: »

I'm looking at 3 inverters, in the 600w range, that I think would be able to start a fridge, but wondering about feedback on how to chose between them

Have you looked at Victron's Phoenix line of inverters? They have some incredibly low tare losses.

--vtMaps

mike95490 · August 2014

Re: mid-power inverter choices

Going to be a standard energy star (frost free) 19CF fridge, so it's likely to have the electronic timer. Drat. forgot about that. No snooze for me.

The SA 1000 looks to be the sure thing to start a fridge, if something else happens to be on. Bummer that it's nearly 20watts idle. Have to double the calcs that BB Bill did.

Sure wish Morningstar came out with a suresine that had enough beef to start a fridge. That would be sweet. I wonder what Midnight's inverter offering will be?

BB. · August 2014

Re: mid-power inverter choices

My"cheap"fridge and freezers have a simple clock work motor timer. It may be possible to wire the motor to a separate small ac inverter. However even the small tsw inverters seem to use 6 watts or so. Probably not worth the cost, time, or expense (or use a DC timer to drive the defrost circuit/cut the compressor.

-Bill

Rybren · August 2014

Re: mid-power inverter choices

I have the Samlex PST-1500-24. It has dual output - hard wire and GFCI and both can be used simultaneously. Tare is ~18W, no snooze/standby function. It starts and runs a 1200W microwave without a hiccup, and I suspect that it will start a fridge.

mike95490 · August 2014

Re: mid-power inverter choices

vtmaps wrote: »

Have you looked at Victron's Phoenix line of inverters? They have some incredibly low tare losses. --vtMaps

only 5 watts for the 24v/1200w version But not sold in North America except for the small 12V models.

vtmaps · August 2014

Re: mid-power inverter choices

mike95490 wrote: »

only 5 watts for the 24v/1200w version But not sold in North America except for the small 12V models.

try: http://baymarinesupply.com/store/electrical/chargers-inverters/victron/victron-phoenix-24-1200-inverter.html

by the way, the only reason I haven't bought one is that they are not listed for hard-wiring into a system. They have some sort of marine listing/certification.

--vtMaps

westbranch · August 2014

Re: mid-power inverter choices

Mike, check out the Cotek line http://www.cotek.ca/

Photowhit · August 2014

Re: mid-power inverter choices

Cariboocoot wrote: »

The Exeltech 600 might start one, depending on what other loads are on at the same time....

...None of these are designed to be hard wired,...

The Exeltech is hard wirable, the exeltech XP1100 is about $100 more than the 600 and they have an optional setup to run at 10watts rather than the standard 20watts, I would call NAWS and ask about that. I'm sure the XP1100 would run most any fridge, one person here has a fridge and a freezer as well as assorted other items running on an XP1100. These also have a wiring enclosure so you can run your wiring in conduit to the inverter.

NAWS has a very good price on the XP1100, and they say pretty good stuff about them!

We have been selling Exeltech inverters for over 15 years, and we have never had one single report of any failure of any type. In fact, we have never even heard of one going bad that was not grossly abused (i.e. like hooking the battery terminals to AC power).

Exeltech inverters have an MTBF(mean time between failure) in excess of 20 years and offers the most competitively priced ultra-reliable true sine inverters available anywhere

And Exeltech via NAWS (and I hoped they checked this since they just updated their website)

...We also still support and repair units from 20 years ago, and do so for a flat fee. Case in point: If you accidentally reverse connections on an XP1100 inverter you bought in 1994, or an MX module from 1993 .. or even an old SI1000 from 1991, and blow it up .. if it's repairable, we'll fix it for $100 and (if possible) upgrade it at the same time. Turn-around time generally averages less than a week.

Made in the USA...FWIW

Here is the back showing the user neutral ground bonding at the hard wire points, which can be removed, it also has outlets on the other side.

Attachment not found.

mike95490 · August 2014

Re: mid-power inverter choices

oh goodie ! more choices !!

Saggys · August 2014

Re: mid-power inverter choices

The Exceltech XP1100 looks good. I just question the size of the conduit knockouts and wire bending space in its AC/DC enclosure.

Photowhit · August 2014

Re: mid-power inverter choices

You can take the enclosure off, I wired my xp1100 somewhat light, with 4 gauge about 18 inches from breaker (heavier to battery) I don't think I would have any problem with 2 gauge, then again I ran 4 - 4gauge in 1 inch (max allowed) The knock outs are is 3/4".

mid-power inverter choices

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