360 Aircon Relay box - Where is it ?

[vik1111]

Hi,

I have a Carver 360, with 2 Aircon units (Saloon & Fwd) sharing 1 sea water pump. Switching on the FWD unit brings the water pump to live, but the pump doesnt run when just the Saloon unit is ON. Was expecting to find a Relay units close to the pump or the compressor but no joy. All the cables (from each compressor & pump) seems to be running to main AC board but i just cant seem to find the relay. Any help would be much appreciated !

Thanks in advance.

[Viper]

Welcome aboard.
All the relays should be in the control box that the cabling is running to as you describe above. The relays aren't that big, usually small black cube. You may be overlooking them because you're expecting to see something larger. They're usually right after the terminal block where the cables get hooked up. I don't know what vintage you have but newer units might use electronic drivers instead.

Is this boat new to you? Did this just start or has it always been this way? Do you get any cooling or heat from the suspected unit? How have you confirmed the water pump isn't running for that air conditioner? Do your remote control panels have digital displays? If so, the unit should display a fault code if it doesn't get water after a short period as that would affect the refrigeration system pretty quickly.

[vik1111]

Viper

Thanks for the reply.

I bought the boat last year (after market) and started experiencing this problem 1-2 months ago, straight after an upslip.

Attached are some photos, hopefully it helps.

Do you get any cooling or heat from the suspected unit?
The Saloon unit cools intermittently. I am told this is because it shares a pump with the forward unit. Ie. Saloon cools as long as the inside compressor is running.

How have you confirmed the water pump isn't running for that air conditioner?
1) Physically not running
2) No water outflow from external outlet
This is not the case when the forward AC is running. The pump kicks in as soon as the forward compressor starts.

Do your remote control panels have digital displays?
It occasionally displays 'HPF'

Refrigeration seems to work fine at this time.

Any help will be appreciated greatly. Thanks in advance.

[bud37]

Welcome to the forum and Carver .......what year is your boat, if you could put that in the vessel info it may help on anything further that comes up.........HPF may be a water flow issue of some kind.........

[vik1111]

Hi

Its a 2007 Carver 360.

Both aircon are Marine Air (Dometic).
Saloon aircon – VCD12KZ/2
Forward aircon, - VCD12KZ/2.

Thanks

[Viper]

That code indicates a High Pressure Fault meaning your high pressure switch is open. In cooling mode, this is indicative of low water volume due to a malfunctioning pump or a restriction due to a kinked line, clogged strainer, restricted condenser, etc. During a heat cycle, it's usually due to restricted air flow from either a dirty filter, faulty fan, ducting, etc.

If you're sure the raw water pump does not turn on when you run this particular AC unit then it must be a control circuit problem. The bonus here is that you have two controllers. I suspect yours is new enough to have the telephone cable type connector. Sometimes the contacts get corroded so pull out the connector from the back of the panel then push it back in. Do this several times then try turning the unit on and see if it activates the water pump. If it doesn't, repeat the above at the control box below deck, then try again. If it still doesn't work, swap the panels and see if the fault follows the panel to the other unit. If it does, it's likely the panel, if it doesn't the problem is likely in the control box.

Sharing the same raw water pump is not the reason for intermittent operation. As long as the pump is of the correct rating, you can have multiple units running off the same pump. In fact, you usually don't see two pumps in an application until you get into 4 or more AC units.

Let me ask you this; when your forward unit is running, do you see water discharging from the salon unit? You should!! As soon as the pump comes on, it circulates water to ALL AC units, even the ones you don't have turned on. In other words, if everything else on the salon unit is working except that it won't turn on the water pump for some reason, you could get around that by turning on the the fwd unit which you know is activating the pump. It should then also supply water for the salon unit to operate normally. I think you might have more than one thing going on here.