webasto fcf reverse cycle unit tripping breaker using heater

[89Vision32]

*i use a single 30amp shore power*

Ive been using the heater for over a month and the past week it started tripping from the cycle surge spikes. But never the first startup one. Normally when the cycle starts it surges up to about 40-50 amps then immediately settles down and runs fine. The reverse cycle kicks over and it heats the boat up. after a couple of cycles usually more than an hour later it surges amps again and then the amps stay up there until it flips my main breaker off. I cant figure out what is causing this. All the wires and connections look good as well as the condition of my shore power cable. Ive tried turning everything else on my 120 panel off besides the AC and it didn't help.

anyone else have a similar issue?

 

[jssailem]

Your description sounds like you are talking about the shore pedestal breaker.

You are having a cold spell.
Check your BTU unit here.
The surge current could be greater than the Breaker.

The breaker may have aged.

If your unit is the 16000, a slow delay breaker is recommended. Check the breaker meets the requirement. P_erhaps install a new breaker if it is the one on your boat that is popping.

 

[dlochner]

It may not be the heater, it may be the other things you are using, a few more lights, the refrigerator coming on, watching TV, on the computer. While some of those may be DC devices, if the battery charger is still on, the charger will increase its output to meet the demand.

Check the base load, that is the what is the current draw before the heater comes on. Then check the base load after the breaker trips, turn the heater off and reset the breaker, what is the load?

Some breakers are thermal, when they reach a designated temp, they trip. If the heater has been running a while at a high load the breaker will be warm, a quick surge when restarting can drive the temp above the the threshold.

 

[justsomeguy]

I cant figure out what is causing this.

Filter before the pump clean?

 

[89Vision32]

Filter before the pump clean?

Yes all my filters are clean and my seawater output flow is perfect

 

[89Vision32]

Your description sounds like you are talking about the shore pedestal breaker.

You are having a cold spell.
Check your BTU unit here.
The surge current could be greater than the Breaker.
View attachment 229523

The breaker may have aged.
View attachment 229524
If your unit is the 16000, a slow delay breaker is recommended. Check the breaker meets the requirement. P_erhaps install a new breaker if it is the one on your boat that is popping.

That table is super helpful thank you! The amps are spiking up to 54 when it's surging but after the initial surge lasting barely a second later on after the unit's been running for a while when it starts again it's lasting like three to four seconds and that's what's tripping it. I'm not sure why the amps spiking up like that and lingering there after the unit's been running. I've been considering getting a soft start for it but I don't want that to Band-Aid underlying problem if I have one

 

[jssailem]

What is the age of the unit? The compressor is the challenge. Is the freon level proper?
Is the breaker on your boat or on the shore pedestal?

 

[jssailem]

A soft start will help to mitigate the surge.
You stated that all the wiring and connections are clean. Is the cable size 12awg as indicated in the installation instructions?

 

[89Vision32]

What is the age of the unit? The compressor is the challenge. Is the freon level proper?
Is the breaker on your boat or on the shore pedestal?

The breaker on the boat is what's tripping. The unit is around 5 years old with all the proper size wire. The unit runs fine for hours with the AC running and only trips when using the heat so I'm thinking it could be related to the reverse flow switch. But I just don't know why it wouldn't do it everytime it cycles and only after its been running for an hour

 

[jssailem]

I'm thinking it could be related to the reverse flow switch.

Now your moving into the HVAC world where my knowledge base is skinny at best. Hopefully one of the wizards in this area on the forum will step in.

 

[dlochner]

The breaker on the boat is what's tripping. The unit is around 5 years old with all the proper size wire. The unit runs fine for hours with the AC running and only trips when using the heat so I'm thinking it could be related to the reverse flow switch. But I just don't know why it wouldn't do it everytime it cycles and only after its been running for an hour

The assumption you are making is the problem lies solely with the heating unit that may not be correct. The main breaker will trip if the total AC consumption is greater than 30 amps (actually a little higher because of the delay built in to the breaker to avoid nuisance trips). Eliminate all the other loads on the AC circuit, i.e, unplug everything and turn off the charger. If the unit still trips the breaker, then your assumption is correct and look to the heating unit. If the unit does not trip the breaker, then the problem is the total AC consumption. Then it is a matter of what you can do without while staying warm.

 

[kloudie1]

Listen for the heat/cold reversing solenoid to release the high side pressure a few seconds after a thermostat shutdown. If that solenoid does not release the pressure, the next start could draw a lot more amps.you could have a sticky solenoid. You could unplug the solenoid and use a jumper wire to exercise it while the unit is off. Don't, if you are not well versed in working on electrics safely.

 

[89Vision32]

Listen for the heat/cold reversing solenoid to release the high side pressure a few seconds after a thermostat shutdown. If that solenoid does not release the pressure, the next start could draw a lot more amps.you could have a sticky solenoid. You could unplug the solenoid and use a jumper wire to exercise it while the unit is off. Don't, if you are not well versed in working on electrics safely.

That may be it. Now that I think about it through out the day I would hear the reverse switch kick over every time it cycled on. Recently I'm only hearing it during the initial start up. When I get back to the boat I'm going to look at this closer