Chiller troubleshooting

they re on freq drives so no surge at start up. They slowly ramp up. And they trip the breaker while running.

The Dometic chiller control cabinet is powered by two 63 amp breaker from the main panel.

1 breaker powers chiller 1 & 2, the other powers chiller 3, the circulation pump and the sea water pumps (two installed with a selector switch. It s the breaker to chiller 1 & 2 that trips.

Inside the control cabinet, each pump and chiller has its own breaker. Problem is that the individual chiller breakers are 40 amps each. So... if for some reason each chiller pulls 38 amp and the other one 30, the main panel breaker will trip.

shores power goes thru an Atlas system which keeps voltage and freq spot on. Plus the boat monitoring system would alert me if voltage had dipped

with chillers the air handlers (on their owner breakers) do not control and are not linked to the chillers and compressors. The loop temp is monitored by the chillers control which activates them as needed to keep the loop at the set temp

lol welcome to south Florida and our currently 92 deg sea water vs 71 in NJ

again, these have frequency drives and ramp up slowly. No surge at all. And no the tripping occurs while running.

true. We ve replaced both on the 84 over the years, and an ER blower drive as well. But the failure was obvious. Just not turning on, no display. Never tripped a breaker. Anything is possible though

Nr 1 and nr 2 will run forever separately. If both are on, their common breaker trip.

Yesterday I ran them using a clamp on fluke with the max function activated. It never recorded a spike whether when monitoring either chiller or the combined feed. Doing more testing today

both chillers combined run at 55/56 amp on the clamp meter which may be a bit close to the 63 amp breaker. According to the cruisair diagram they should pull 23 each.

going to revisit the raw flow to see if we can lower the temps therefore the amps. Thru hull is clear, strainer is clean, I switched to the second pump. No difference. I m wondering if the pumps aren’t tired with eroded impellers.

We re here in Miami. Happens both on shore and gen

if there was a voltage drop for some reason the Isis would throw an alarm. Our shore power goes theu an Atlas System so it s supposed to be pretty stable. I was in the ER when the breaker tripped; nothing obvious like voltage dip, sound, etc.

Right now it’s been holding for a few hours. The clamp on shows consistent amperage on chiller 2 at 26/27 amps which is a bit higher than it should be

next step is going to be to pull the back up raw water pump and check the impeller for erosion. Age unknown. Coils are hot despite recent descale, they’re around 95 at the bottom and 120 at the top.

I m not sure if it s 80% but ideally yes you want some margin. Problem in this case is that this type of euro breaker tops at 63amp. Getting a higher rating would require panel surgery.

J, water temp is about 90 right now... top of the coils wheee water exits are around 115. The more I look at it the more I think it s a flow issue.