Community Forums

ScopeGuard · 08-16-2018, 04:31 PM

Hi,

I have a 2015 Fleetwood 35B with the typical Coleman 13.5 btu ac units, rear with heat pump. We’ve owned the coach a few months. This week the rear AC stopped cooling. The blower for the ducts runs, evaparator fan motor not starting, compressor not running. I changed out the start/run capacitor and the fan/compressor runs for 3 minutes then stops.

I’m currently on my home 50A shore power.

No issues with the front unit.

Any ideas?

Don

einstein2nd · 08-16-2018, 05:09 PM

I am assuming you are using a 240vac 50amp adapter to power a 125vac 30 amp RV, right?

I have the opposite issue: rear works but front does not.

I am thinking it is low voltage after checking amperage on the 30amp leg. The RV was pulling 28amps on a 30amp breaker.

The Intellitec climate control EMS board test switch turns the front AC compressor on but causes the main breaker to trip. My EMS was behind my load center in the RV. Yours might be there too.

I have pictures via link:
http://www.irv2.com/forums/f61/moderator-edit-new-here-403545.html

RV voltage should be 125vac for 30amp service.

I checked the voltage where I plug my RV in; I was reading 115vac.

The simple fix for my issue is to buy a autotransformer that buck/boosts voltage. I prefer to upgrade to a 240vac source instead.

Check the voltage at the plug while the RV is plugged in. If the voltage is 125 or better; find the EMS and use the test switch to test compressor. If the compressor still fails to turn on; you might need to purchase a new AC. Found them for about $450 online. Quoted by local RV repair shop $900 to buy and install; $700 to buy only. Southern California prices.

If the voltage is below 120vac your source is too low.

Each AC should draw between 8 to 12amps on a 125vac source; any voltage lower than that will increase the amperage causing your EMS to shut one AC down.

Rule of thumb:
when it comes to power consumption:
current is directly proportional to the voltage
Higher the voltage is; the lower the amp draw will be
the lower the voltage; the higher the amp draw will be

Hope this helps.

ScopeGuard · 08-16-2018, 05:15 PM

Quote:

Originally Posted by einstein2nd

I am assuming you are using a 240vac 50amp adapter to power a 125vac 30 amp RV, right?

I have the opposite issue: rear works but front does not.

I am thinking it is low voltage after checking amperage on the 30amp leg. The RV was pulling 28amps on a 30amp breaker.

The Intellitec climate control EMS board test switch turns the front AC compressor on but causes the main breaker to trip. My EMS was behind my load center in the RV. Yours might be there too.

I have pictures via link:
http://www.irv2.com/forums/f61/moderator-edit-new-here-403545.html

RV voltage should be 125vac for 30amp service.

I checked the voltage where I plug my RV in; I was reading 115vac.

The simple fix for my issue is to buy a autotransformer that buck/boosts voltage. I prefer to upgrade to a 240vac source instead.

Check the voltage at the plug while the RV is plugged in. If the voltage is 125 or better; find the EMS and use the test switch to test compressor. If the compressor still fails to turn on; you might need to purchase a new AC. Found them for about $450 online. Quoted by local RV repair shop $900 to buy and install; $700 to buy only. Southern California prices.

If the voltage is below 120vac your source is too low.

Each AC should draw between 8 to 12amps on a 125vac source; any voltage lower than that will increase the amperage causing your EMS to shut one AC down.

Rule of thumb:
when it comes to power consumption:
current is directly proportional to the voltage
Higher the voltage is; the lower the amp draw will be
the lower the voltage; the higher the amp draw will be

Hope this helps.

I’ll check as you suggested but the coach has been on this service, configured as you detailed, since June except for road trips since mid-June. So I’m thinking voltage not the issue. The compressor runs, just switches off after about 3 minutes.

Thanks for the reply.

einstein2nd · 08-17-2018, 10:12 AM

Quote:

Originally Posted by ScopeGuard

I’ll check as you suggested but the coach has been on this service, configured as you detailed, since June except for road trips since mid-June. So I’m thinking voltage not the issue. The compressor runs, just switches off after about 3 minutes.

Thanks for the reply.

If the voltage is good, I heard resetting the EMS does the trick.

I just replaced both my motors on a bounder m36s. I bought the caps too but didn't need them.

My front AC was drawing 9amps and my rear was drawing 8amps.

On the EMS, there is a 3 position test switch: left was rear AC, middle is off, and right is front AC. I switched to front AC and it turned both fan and compressor on.

Before I found the test switch the front AC fan would run. The compressor tried but would immediately turn off.

Also, keep in mind: electricity is not constant. Call your electric company and ask for the peak hours. Check the voltage then.

During peak hours is when everyone uses the most. This is when the voltage drops the most. When you want the AC to run; just think of the thousands just like you turning theirs on too. What happens to the electricity during that time? The voltage drops increasing the amps which then heats up all the electrical devices causing more reduction of voltage due to heat.

The more power that is used the more the devices have to work hard. My electric company offers discounts to those using less power during peak hours because it saves their transformers and power stations.

I apologize, I can talk about electricity all day. I'm a fanatic when it comes to power!

Edit: another thing could be your motor needs to be lubricated or replaced. If your motor and compressor are using the same cap; possibly explains why both shuts off or the EMS senses too much amperage on the motor and shuts them both off (this is if they are on separate caps).

My issue was the compressors both worked but the motors would hum. My motors and compressors have their own caps. I replaced both motors and checked the caps and they all work now. The front AC compressor does not turn on unless I use the test switch on the EMS. I believe it is due to the voltage and amperage.

The reason why I am mentioning the EMS is because it is a good tool to troubleshoot. Using the test switch will turn the compressor and motor on. Leave it on for the 3 minutes and see if it shuts down. If it does then its the AC unit that has the issue; it is doesn't then it could be something else causing the issue.