Giandel 2000 pure inverter

davecdave

When I plug in my furnace (i put a plug on it for this poupose) the gas furnace wont fire. The big blower turns on but no flame. Shows 118 volts using all 12 ga wire and it is a 20 foot 12 ga extention cord. The furnace is gas and it is a Rheem 4 years old

109A_5

Hello @davecdave,

Was it tested prior to now with the whole house off ? Did it ever work this way ? Is there another transformer in the system that is not being powered presently by the inverter ? Everything grounded properly ?

EDIT: Is the inverter output Neutral bonded to the Ground ?

Jamie Hall

It's not uncommon for a gas furnace to require a ground, as well as a neutral...

davecdave

There is no other transformer. The air handler works but the burner wont fire. It is 4 years old and is high efficiency. 
This is the first time I have put it on the inverter.  Shows 118 volts using all 12 ga wire and it is a 20 foot 12 ga extension cord. I just bonded the aishandler to the inverter and the whole house. Still wont fire. Any ideas?

MaxMercy

davecdave said:

There is no other transformer. The air handler works but the burner wont fire. It is 4 years old and is high efficiency. 
This is the first time I have put it on the inverter.  Shows 118 volts using all 12 ga wire and it is a 20 foot 12 ga extension cord. I just bonded the aishandler to the inverter and the whole house. Still wont fire. Any ideas?

Have you put it back on line to see if it fires? (just in case)

mattmia2

What kind of ignition does it use? HSI can draw a lot of power for a moment while it is cold.

109A_5

Hello @davecdave,
What model Rheem gas furnace is it ? Any error codes ?

davecdave

I hooked it back up using a 12 ga extention cord to my power i also ran a line to the next door neighbor to try his power. It worked fine
mod #R92PA0851521MSA

109A_5

Hello @davecdave,

davecdave said:

I hooked it back up using a 12 ga extention cord to my power i also ran a line to the next door neighbor to try his power. It worked fine
mod #R92PA0851521MSA

So utility power from either house works fine and it still does not work with the inverter ?

ratio

109A_5 said:

Hello @davecdave,

<snip>

EDIT: Is the inverter output Neutral bonded to the Ground ?

davecdave

yes the neutral and ground are the same
the codes flash 2 then 9

Jamie Hall

davecdave said:

yes the neutral and ground are the same
the codes flash 2 then 9

That is a problem. You need a separate neutral and ground. That may not cure the problem -- but it surely isn't helping.

109A_5

Hello @davecdave,
Sadly 29 is not in the error code list.



Maybe if you can tell where the process stops it may be a clue.




https://www.theacoutlet.com/documents/Installation-Guide-Rheem-R92PA-S.pdf

PRR

> Giandel 2000 pure inverter
This is a "modified sine wave inverter". That's not normal utility wave-shape. If the igniter is a pure heater (not a sparker) it should work. However a gas burner today is really a computer and may not like "modified sine wave". With the larger loads of "real computers" it used to make a real difference.

109A_5

I do not get the feeling that this is a "modified sine wave inverter", but it could be. It may all be an advertising play on words, to make the power quality seem better than it really is. I suspect the issue is the inverter power quality is messing with the flame detection system, but only @davecdave can tell, and it may easily be something else.



However the harmonic distortion specification is for the Current and not the Voltage "ITHD"
They don't seem to specify the quality of the Voltage or the Frequency stability.

Jamie Hall said:

davecdave said:

yes the neutral and ground are the same
the codes flash 2 then 9

That is a problem. You need a separate neutral and ground. That may not cure the problem -- but it surely isn't helping.

The National Electric Code (NEC) specifies that the Neutral is bonded to Ground at a new or driven isolated power source like an isolation transformer, an inverter probably qualifies as this type of new or driven power source. So the Neutral should be bonded to the Ground at the inverter and the Ground actually Grounded by an approved method.

davecdave

I used a seperate bonding wire and ground

davecdave

I am hoping a Rheem tech reads this.

109A_5

Hello @davecdave,

davecdave said:

I am hoping a Rheem tech reads this.

Even if they do, they probably don't care, since the their intent is for it to work correctly with utility power, which it does, not every inverter or generator the public can come up with. Also I bet Rheem does not engineer or build the control board anyway.

You could contact Rheem and ask then what an error code 29 is. May tell you something, may just be a side effect of the actual issue. Unpublished error codes are probably very rare in the field and may have basically been for engineering purposes.

There is a few things that the furnace control board may not like. The quality of the Voltage waveform, possibly an instantaneous brownout when the inducer motor starts, the Frequency, Frequency jitter, high frequency noise, etc. Does the 24 VAC seem good ? does your multi-meter measure frequency ?

If I was serious about getting a backup power plan, I would try an inverter that publishes better and includes more meaningful specifications (not all inverters and UPSs and generators are created equal). I would also try a generator if you can borrow or rent one for a day. That way you know what works and what does not.

davecdave

any other suggestions

hot_rod

The plugs on both ends of the extension cord wired properly?

davecdave

yes

MaxMercy

There is a possibility that the inverter is momentarily sagging when a load hits it. I've seen electronic power supplies sag and recover so fast a meter can't resolve it (counting rate too slow), but the blip is visible on a scope.

I wonder if a different brand of inverter even of the same nameplate capacity will work fine.

davecdave

I tried running it through a line conditioner but it didn't help. i tried running it through a variac kicked it up to 130 volts no help

dko

Try with a ETL listed UL/CSA certified device. They are safety standards, but points to a better quality unit.
That one has nothing

At least one other unit to test against, instead of putting all your eggs in that one basket.

MaxMercy

davecdave said:

I tried running it through a line conditioner but it didn't help. i tried running it through a variac kicked it up to 130 volts no help

Neither of those things will effect the output of the inverter. A blip on the output side would not be affected by bumping the input (this is an active circuit, not a transformer step-up) or cleaning it up with a conditioner, nor would a post conditioner on the output of the inverter replace an instantaneous dropout.

Now, I'm not suggesting the inverter is blipping on start, and indeed, it's unlikely that would be the reason for the incompatability between your two devices, but I've seen electronic regulators blip so fast the meter doesn't budge but it's visible on the scope. Boring example to follow:

I remember I had a Samsung processor board that would reboot spontaneously on power up. All the voltages were dead on. When I heated the board, the board would start and boot normally. All the voltages I charted were identical cold to hot. I ended up subbing each regulated source one by one and when I fed in an external 3.3 to replace the on-board standby 3.3V source, the board started every time. The on-board regulator read exactly 3.3 but was actually the problem. What happened is that when the processor started and imposed a load, the 3.3V source blipped to 2.5V as seen on a scope (not seen on a DMM) - enough to cause the processor to reboot. It turned out the 3.3V reg IC was bad. I replaced that and again it read 3.3 in standby, but did not sag under start. Lesson learned.