Puzzling Basement A/C problem

[Snowwing]

I have a peculiar problem with my basement A/C in my 2000 Journey. I believe one compressor is having trouble starting. Here are some examples:
With nothing else running and both #1 & #2 AC breakers on and the thermostat set at greater than 5 lower than ambient , amp draw is 16 amps. About once every minute the draw kicks up to 44 amps and bogs the generator down.

With only the #1 A/C breaker on the constant amp draw is 7amps and about once every minute it kicks up to 44 amps and again bogs the generator down.

When on 50 amp shore power and standing outside at the rear by the A/C units you can hear what sounds like a compressor trying to start unsuccessfully and kicking off about once a minute.

Setting the thermostat at less than 5 degrees lower than ambient doesn’t seem to change anything.

The puzzling part is when both breakers are on the amp draw is about twice when only one is on – I think indicating that both compressors are running! The unit is definitely not cooling like it has in the past.
Anybody have a suggestion. I have searched the forum and am ready to tear into the unit as per Duner’s (Bill Elsenpeter) instructions but thought some prior information would be helpful. Thanks in advance.
RC

[Ol'Joe]

Hi Snowwing,

I had a something like that happen just after my No. 1 Start Capacitor fried. Got it replaced and all's been fine since. Hope I helped, Good Roads to YA.

[KIX]

Originally Posted by Snowwing

With nothing else running and both #1 & #2 AC breakers on and the thermostat set at greater than 5 lower than ambient , amp draw is 16 amps. About once every minute the draw kicks up to 44 amps and bogs the generator down.
This DOES sound like #1 is running and #2 is trying to start. But 44 amps may be an indication of a faulty compressor.

With only the #1 A/C breaker on the constant amp draw is 7amps and about once every minute it kicks up to 44 amps and again bogs the generator down.
This SOUNDS like only the outdoor fan is running and both compressors are trying to start at once

The puzzling part is when both breakers are on the amp draw is about twice when only one is on – I think indicating that both compressors are running! The unit is definitely not cooling like it has in the past.
Can't understand this ...... look at your 1st paragraph.

[COLOR="Blue"]Typically the most amps you should see on #2 comp startup is about 30. The fact that you're seeing 44 indicates #2 is not starting due to an internal compressor problem.
My suggestion is that you go to Welcome to RV Comfort and then "work" your way to a service manual for your model #. There is a step-by-step rroubleshooting guide in the manual. Model # is on aft end of unit, external. [COLOR]

[Roadking]

Snowwing --- from your description it sounds like compressor number one is NOT running and is trying to start. Awhile ago I measured the following current draws on my basement air: Indoor fan on low: 2.5 amps on high: 3.5 amps. Compressor 1: 6.7 amps, compressor 2: 6.7 amps. Out door fan on Low: 3.5 amps on high: 4.5 amps. The outdoor fan runs on low when one compressor is running and runs on high with both compressors.

With AC #2 breaker off, you should have a reading of approximately 13 amps. This would be the indoor fan, outdoor fan, and compressor one.

With both compressors running you should have a reading of approximately 21 amps.

WHen a compressor attempts to start you will get a surge. I believe mine surges into the mid 30's for about a second and then settles down. The generator handles this surge and does not load down. A surge of 44 amps seems pretty high.

I'm just guessing here, but my bet would be the start capacitor for compressor number one. If you feel comfortable with working on the electronics you can swap the start capacitor for the number one and number two compressors. After swapping turn only the #1 breaker on and see if the compressor starts. You should be able to hear it and you should have an amp reading of approximately 13 amps.

[dengraham]

My #1 capacitor went bad last year also. Just take the cover off and look at the capacitor to the left. Mine was soft, oily, greasy, messy looking. In fact the sticky stuff was all over the side and bottom and keeps plugging up the drain hole. But, it is an easy replacement and works has been working fine for over a year.
>> Dennis

[Snowwing]

Roadking you may be right. When my # 2 breaker is off there is no AC, no indoor fan and no outdoor fan. I do have a burned capacitor and have a new one and a spare on the way - actually it is a "hard start kit" which includes the start capacitor and wires another part that goes between the capacitor and the wire. When the burned start capacitor is disconnected and both breakers on it runs smoothly but of course only one compressor is on-line - I will assume #2. Thanks again everyone for the help and I will post when I get it repaired.
Ron

[Snowwing]

Received my "hard start kit" today and installed - problem solved. Thank You for the great advice.
Ron

[NeilV]

Originally Posted by Snowwing

Received my "hard start kit" today and installed - problem solved. Thank You for the great advice.
Ron

Ron,

That is what I thought however the root cause is usually low voltage damage. Many (most) campgrounds are not adequately wired and have low voltage which heats up the starter circuits causing them to fail prematurely.

To get rid of the cause you need to install an AutoFormer to boost the voltage back up to where it should be preventing any future low voltage damage.

Since I installed my AutoFormer I have had no more starter and start capacitor failures in my basement air unit.

Since the local dealer had them for around $25 per capacitor/starter set I replaced them both. If one went the other probably is not that far behind.

[Fossilhog]

Low voltage, that's the keyword. I went thru the same thing for 4 years until I got an autoformer. Also, on generator, the 2nd compressor is direct to the gennie and shows no amperage reading of the EMS panel. Took a few yearas and a few advisors to teach me that!

[ARROWVP38]

Winnie Adventure 38' 2007. COLEMAN/MACH 240V HEAT PUMP NO MODEL#'S @ THIS TIME . AUG 2 09 BULLHEAD AZ 117 F AMPS ON AMP METER 27AMPS, THERMOSTAT AET FOR 80F . T'STAT SHOWED 99F NEVER DROPPED. TRU/AIRE T'STAT IS IN THE FRONT, RETURN AIR UNDER THE REAR BED. ( OVER 5FT FROM THE THERMOSTAT ) EXHAUST FROM THE CONDENSOR BLOWS OUT OF THE BOTTOM OF THE A/C UNIT , WHICH THEN IS DRAWN BACK INTO THE CONDENSOR . THIS WON'T WORK ANYBODY ELSE WITH THIS PROBLEM OR DID I GET A LEMON!!!!!!!

[NeilV]

Originally Posted by ARROWVP38

Winnie Adventure 38' 2007. COLEMAN/MACH 240V HEAT PUMP NO MODEL#'S @ THIS TIME . AUG 2 09 BULLHEAD AZ 117 F AMPS ON AMP METER 27AMPS, THERMOSTAT AET FOR 80F . T'STAT SHOWED 99F NEVER DROPPED. TRU/AIRE T'STAT IS IN THE FRONT, RETURN AIR UNDER THE REAR BED. ( OVER 5FT FROM THE THERMOSTAT ) EXHAUST FROM THE CONDENSOR BLOWS OUT OF THE BOTTOM OF THE A/C UNIT , WHICH THEN IS DRAWN BACK INTO THE CONDENSOR . THIS WON'T WORK ANYBODY ELSE WITH THIS PROBLEM OR DID I GET A LEMON!!!!!!!

The unit I believe is 110V not 240V.

Are you on a 30 or 50 amp service?

You are pulling 27 amp on just the ac or is that the combined load? What is power management doing? If you are pulling other loads such as coffee pots, microwave etc it will shut down the second compressor and only run half the system if you are on a 30 amp service.

What is the temperature of the air comming out of your ceiling vents and how is the flow? New air filter and coils inside and out cleaned recently?

With 117 degree temps you are probably experiencing brown outs so your system will not be able to keep up very well. Do you know what the voltage readings at the power post are?

Outside is there any cold air flowing from under the rear cap? Could be a duct leak up there.

Full sun or is the coach in the shade?

Did you just recently purchase the coach?

The outside blower has been in that configuration since the early 1990's and has not been a problem.

Note that all caps is considered shouting and some will ignore your post for that.

Most common problem are dirty filters/coils, low voltage and duct separation in the rear cap. In low voltage situations you may burn out your compressors starter circuits. The replacement capacitors and solid state starter sets should be about $25 and you need 2 sets. Some have problems if they have items blocking or are parked where the exhaust from the outside blower can't flow very well out to the left side of the coach.

If you just got the coach then the system probably needs a good cleaning and may need the starters replaced. A Hughs AutoFormer will help with brownouts and the associated damages.

When it is almost 120 degrees out remember to close the blinds and put sunscreens over the front windows. The windsheild can act just like a big magnifying glass.

Be mindfull that 20 to 30 degrees temperature differential is about the max you are going to get on an AC system especially in extreme situations so minimizing heat from appliences, opening doors/windows and use of sunscreens/awnings can be critical.

[KIX]

Originally Posted by ARROWVP38

Winnie Adventure 38' 2007. COLEMAN/MACH 240V HEAT PUMP
EXHAUST FROM THE CONDENSOR BLOWS OUT OF THE BOTTOM OF THE A/C UNIT , WHICH THEN IS DRAWN BACK INTO THE CONDENSOR . THIS WON'T WORK ANYBODY ELSE WITH THIS PROBLEM OR DID I GET A LEMON!!!!!!!

Doesn't sound like a lemon but it does sound like you don't understand the A/C air flow dynamics. The indoor air is simply recirculated from the indoor return air plenum then across the evaporator coil and redistributed through your duct work. The outdoor air blower blows outdoor air across the condenser coils and is then dissipated to the outdoor atmosphere. There is no mixing of indoor and outdoor air as the unit is designed.

NEIL V provided some good information for you to consider. If I had to make a guess of the high amperage cause, assuming the A/C is the only load, my guess would be low voltage. NEIL V gave you some causes for the low voltage you should check out.

And by the way your A/C is not 240 volt. There are two separate 120 volt circuits going to the A/C unit.

Hope all this helps you.

[ARROWVP38]

Originally Posted by NeilV

The unit I believe is 110V not 240V.

Are you on a 30 or 50 amp service?

You are pulling 27 amp on just the ac or is that the combined load? What is power management doing? If you are pulling other loads such as coffee pots, microwave etc it will shut down the second compressor and only run half the system if you are on a 30 amp service.

What is the temperature of the air comming out of your ceiling vents and how is the flow? New air filter and coils inside and out cleaned recently?

With 117 degree temps you are probably experiencing brown outs so your system will not be able to keep up very well. Do you know what the voltage readings at the power post are?

Outside is there any cold air flowing from under the rear cap? Could be a duct leak up there.

Full sun or is the coach in the shade?

Did you just recently purchase the coach?

The outside blower has been in that configuration since the early 1990's and has not been a problem.

Note that all caps is considered shouting and some will ignore your post for that.

Most common problem are dirty filters/coils, low voltage and duct separation in the rear cap. In low voltage situations you may burn out your compressors starter circuits. The replacement capacitors and solid state starter sets should be about $25 and you need 2 sets. Some have problems if they have items blocking or are parked where the exhaust from the outside blower can't flow very well out to the left side of the coach.

If you just got the coach then the system probably needs a good cleaning and may need the starters replaced. A Hughs AutoFormer will help with brownouts and the associated damages.

When it is almost 120 degrees out remember to close the blinds and put sunscreens over the front windows. The windsheild can act just like a big magnifying glass.

Be mindfull that 20 to 30 degrees temperature differential is about the max you are going to get on an AC system especially in extreme situations so minimizing heat from appliences, opening doors/windows and use of sunscreens/awnings can be critical.

Great Info. my fault i assumed 240 1ph, you both are correct 115. power for shore line should be 240 1ph/neutral/ground 50 amp. now winnie does not supply a hold down for the indoor filter. so i have inspected the indoor coil , not impacted /clean like brand new, so i secured the filter in it's channel with velcro.that should stay clean /changed on a 30 day. out door condenser blower is 8 x 8 hole screen over the hole, it blowes down to the ground 2ft or so,then hot air is pulled into the condenser coils effecting sub cooling.duct work 8x8 up the back of the to the ceiling duct,it also is insulated and all tight. inside blower air seems to be good on hi spd. now i didn't have other items on no h/w,m/w ect. all blinds are down, frt windshield has a silver shield and curtains dwn.also condenser coil is spotless.not impacted. we had no tree shade,cement pad,desert dirt/gravel. I did by this winnie brand new 1000miles on her. energy panel amp gauge was at 27. could there be a problem at the transfer box were the main shore line comes into . should pull out my fluke meters get exact input power.amp draw i was told 20 degree split on the a/c temps

[KIX]

Arrow, At this point I think a thermometer is your best diagnostic too.. Check the temp difference between the return air at the filter and inside the supply duct near the rear of the coach. If you have approx 20* difference then your A/C is doing all it's going to do.