New Twist on Old Air

[egaito]

With the woes we have lived through, and the $$$'s we have paid to keep the old, and new, Cruisair units running, we've done a lot of research to understand how the systems work. Cruisair (corporate and dealer) has told us several times that there is no replacements for the control boxes and circuitry at this point, which I've never quite believed. It is trying to keep the old relay/triac/wiring diagram from hell going that has caused more negative cash flow on the boat than any other system thus far.

So growing tired of hearing about assembly's, parts and systems that aren't made anymore, I started thinking that there has to be some generic controller out there that can control the system with fewer moving (and unavailable) parts. These system are all basically a collection of the same, or very similar parts....thermostats, condensers with compressors, pumps, reversing valves, evaporators with fans, over-pressure and under-pressure switches, capacitors to keep you on your toes. Aren't they? There has got to be an industrial controller or something out there.

I talked to a dock buddy who knows his stuff in this area, and he in turn dragged me over to a factory that makes marine air for a lot of large and complex vessels.

Well, as it turns out, they have a box/board that is fairly generic in nature, uses nice, modern digital thermostats, and seems to have all of the inputs, outputs and voltage levels that match up with the existing systems. Their box and thermostat, as best I can tell at this point, would replace the 3 position switch, mechanical thermostat, and the big blue/gray box with the breaker and that crazy-fun triac in it. It will control the pump, in our case by sending a signal to our new pump relay box where all the other systems send their signals. Overpressure and underpressure are handled, with error codes being fed to the displays. The engineer there said as long as there are enough original wires there to carry the signals (no problem there!), it can be wired in. The biggest hassle in our case would be running the telephone cord interface cable between the box and the thermostat. I'm sure with some creative thinking, a drill, and a sawsall, I can figure that out.

I've been told that anything that seems too good to be true probably is. The thermostat and box are under $500, not installed of course.

There was no hard sell here, in fact he didn't want to sell it to me based on the age of the system, until I pointed out that the price amounts to less than a day of labor by one of the "professionals" we've given thousands to already, and if it saved only one service call between install and melt-down of the rest of the system, we would be ahead of the game, and even if the system does let out it's smoke, the new controls will work with a new one.

Am I missing anything here?

 

[fissioneng]

It sounds like you're describing the FX-1 control from Coastal Climate Control (Micro-Air). They are at www.coastalclimatecontrol.com . I know that Sky has installed these as have others, I will too, just not now. I think it can take all the PW-somethings (triac devices) out of the system and seems to work well. They OEM to Mermaid I believe.

If you want to be daring, you can look at something like a Honeywell T775, but wiring that in will take a little bit of ingenuity.

 

[SKYCHENEY]

Ed,
Call me if you need help, but I have installed a couple of those CCC controllers. They will replace all of your controls and control boxes as long as the compressors are 16K units or smaller. Anything larger and you will also need a relay that is heavy enough to take the starting load. That relay only costs about $20 and the CCC box and panel is about $400.

The controller is fully programmable and will start and stop the sea water pump, fans, etc with or without the compressor. It also has the dehumidify function which would come in handy in S FLA.

With no PWX box, you will have no triacs and no triggers except in your pump control box. That too could be removed with just a few more off-the-shelf parts. I haven't gotten that far yet, however.

 

[egaito]

Ed,
Call me if you need help, but I have installed a couple of those CCC controllers. They will replace all of your controls and control boxes as long as the compressors are 16K units or smaller. Anything larger and you will also need a relay that is heavy enough to take the starting load. That relay only costs about $20 and the CCC box and panel is about $400.

The controller is fully programmable and will start and stop the sea water pump, fans, etc with or without the compressor. It also has the dehumidify function which would come in handy in S FLA.

With no PWX box, you will have no triacs and no triggers except in your pump control box. That too could be removed with just a few more off-the-shelf parts. I haven't gotten that far yet, however.

Well, it sounds like its not only do-able, but has already been done!

The company I was talking to isn't CCC, but I suspect the controller is the same. The guy that took me over there brought a Cruisair box that he had blown the circuit board on, and they had a direct replacement. It seems a 3rd party makes the board that most of the system vendors use.

The Honeywell looks interesting, particularly to the geek in me, but I like the idea of the purpose built circuit.

I purposely left the brand out so the discussion didn't wander in that direction immediately. The folks I spoke to are at AquaAir in Miami. We were given a tour of the factory and got to see some interesting stuff under construction for 100+ footers. I got a good feeling from everyone I met. Very knowledgeable and extremely helpful.

I could have spent all day going through the book shelves of notebooks labeled with boat names.

Sky, what was the biggest challenge putting yours together?

 

[SKYCHENEY]

Ed,
The biggest challenge is identifing what each wire does. Hatteras diagrams are a big help, but they do not use the standard colors for each function like Cruisair does. So, you have the standard colors coming from each compressor but from the PWX box to the thermostats you have all brown wires with different colored stripes on them.

Many of the old wires are no longer used and can be removed such as the ones from the old juction box to the old thermostat (the new wire to the control is just a network cable).

Once you have correctly identified the wire for the compressor start, reversing valve, fans, pump control, etc., it is quite easy to install. The new box from CCC is labeled well and there is plenty of room in there to connect all of the wires to the board. The whole thing is really quite simple after you figure out what wire goes to what. Part of the problem is getting the Cruisair and the Hatteras wiring diagrams out and matching everything up. The Hatt drawings show the wires up to the Cruisair stuff and then you have to look at the CA diagram from there on.

You can leave the high and low pressure cut-outs as they are or you can wire them to the new box. As they are, they are just in-line and they interupt power to the unit until the pressures are within spec. That is okay, but I'd rather have the fault show on the panel and not have the compressor cycling on and off. If you wire the cutouts to the new box, you may have to run some extra wire or you may have some spares or unused wires that you can use.

It sounds like you have a good contact at Aqua and the price is not out of line. If you decide to go with CCC, their tech help line is good. The guy there will help you over the phone if you run into trouble. Don't be afraid to tackle this on your own if you can read a wiring diagram. It's just not that difficult.