remove (built-in) temp controller from chiller - always on?

[wizsmaster]

I'm looking to remove the temperature controller from my chiller, so it will always be on when power is on. I'd rather control the temperature with my AC3, than the built-in temp controller on my CW1000 chiller.

Can someone lead me in the right direction, or provide instructions on how to go about this?
There are 4 wires + temp sensor on the PCB.

Wire Color (Label on PCB) - Voltage (chiller state)
-----------------------------------------------------------
Black (AC_N) - 120v (OFF)
Gray (HEAT) - 120v (OFF)
White (on "COMP) 120v (OFF) / 2.9v (ON)
Blue (on "COMP") 120v (OFF) / 2.9v (ON)


Wire connect to
-------------------
Black -> Gray & white to fan
-> Blue to Starter (?)
-> "+" power in (positive)
Gray ->Heat Cutoff on copper?
Blue -> Blue on compressor
-> Black on Fan
White -> "-" on power in (negative)


Thanks,

marco

[wizsmaster]

This is a 120v 1HP chiller.

[snorvich]

Do you think the AC3 is more accurate? Have you calibrated either the chiller or the AC3?

[wizsmaster]

they are about 2*F off each other - however i like being able to control it with one, also build in some fail-safes - to NOT burn up the chiller if the pump, or flow stops etc.etc.etc.

[wizsmaster]

here is the PCB

[lakee911]

Why don't you just set the chiller stat at like 50 degrees and it will always come on?

Actually, setting it a little lower than what you'd ever have it go down to would be a good safety precaution should your controller fail. I do that with my heaters.

They're set at 82degrees and my temperature controller is set to like 79, so if the controller fails, then the tank will never get past 82.

Jason

[wizsmaster]

because i've had these built in units fail ... i've had one that prevented the chiller from coming on, and i've had one that kept it on. I would much rather just disconnect it, and run it off my AC3!

[MeuserReef]

Just find the hot and common voltage going into the thermostat (PCB). Now find where the 120V comes out of the thermostat and where it connects to the compressor/capacitor (may require a volt meter). Then just bypass the built-in thermostat

[wizsmaster]

Well ... I dont thibk it will be that easy.

The grey wire has 120v on it when the chiller is off, and 2.9v when the heater comes on - this chiller is a chiller/heater combo, but it uses the compressor to heat, rather than a dedicated heater.

[MeuserReef]

In that case.... I dont know.

Do you have any documentation (ie. wiring diagram) that came with the unit? (Im guessing that if you did, you would have posted it.)

Its going to be tough to figure this one out remotely.

Good luck.

[Donw]

Do you have a volt meter? If so we should be able to figure this out real quick.

Don

[wizsmaster]

yes, little chap one from radio shack - but yes.

[ShipOFools]

can you take a pic of the schematic? Thermostat is nothing more than a switch it will be line in line out all you need to do is remove line in run to ac3 and attach other side of sc3 to wire coming out of stat, if this is heating also need to know if a call for heat or call for cooling energizes the reversing valve, If i had to guess it fails to cooling and energizes to heat

[Donw]

Originally posted by wizsmaster
yes, little chap one from radio shack - but yes.

Of course your going to loose heat mode. Anyways we need to know what each wire does and when. Put the N of your meter in the wall on the N side of the outlet.
Use the hot side of you meter and check voltage on all the wires with chiller and heat off, write down what you get. Now do the same in chill mode. Then the same in heat mode.

Don

[MeuserReef]

Originally posted by Donw
Of course your going to loose heat mode.

If it meant losing heat mode, I wouldnt mess with it. You have a better chance of failure with many of the other components on a reef system to go hacking into a $1500 chiller IMO.

[Donw]

Originally posted by MeuserReef
If it meant losing heat mode, I wouldnt mess with it. You have a better chance of failure with many of the other components on a reef system to go hacking into a $1500 chiller IMO.

I'm sure he can just get heat mode with another outlet on the aquacontroller.

Personally I wouldnt trust a aquacontroller to control tank temp. I think they are fine for a backup. Ive seen quite a few tanks meltdown because of ac temp probes.

Don

[wizsmaster]

Originally posted by Donw
I'm sure he can just get heat mode with another outlet on the aquacontroller.

Personally I wouldnt trust a aquacontroller to control tank temp. I think they are fine for a backup. Ive seen quite a few tanks meltdown because of ac temp probes.

Don

I'll be quiet honest - I've seen them too. I have however seen quiet a few tank meltdowns due to failed chiller temp controllers. Like the guy whom i picked up the entire LR content of his "used to be" in the wall setup - left for the weekend ... and a slightly cold water reef & lobster tank is what was left of it.

On the AC3 i know i will have to replace, and am able to replace the probe every so often - with th AC3 i will also be able to build in failsafe controls - and in my case, i'm planning on running 2 temp probes (px1000).

The chiller on the other hand, the temp probe is in the barrel, i have NO idea how long it will last, or where to get another one, let alone how to replace it.



I am a little hesitant to do this project - 1st of all, i don't like burning up a perfectly fine working slightly expensive chiller.
2. I'd prefer not to loose the heat, eventhough i'm almost certain that I could build a relay box to enable the heat & chilling - i believe the heat is activated through a switched manifold that transfers the hot gas from the compressor to the chiller barrel, instead of through the fan/radiator first.

Maybe this weekend i will get some time, and take the voltage meeter to the unit, and see exactly what is switched on when, and how i could replicate it w/out the built-in compressor.


This is NOT a PCI brand chiller, eventhough it has the same outter box, and guts. I got it from my LFS, they got it from their supplier .. i spoke to PCI today .. they didn't offer any help in doing this.

[funman1]

Ok this MAY be really easy..

YOU MUST MAKE SURE that the chiller is on the same circuit as the AC controller strip..

If it's anything like mine, the black is power always ON from the wall plug, the white is always on neutral from the wall plug.

The gray should turn the compressor on in one direction (IE: Cold on the water coils, hot on the fins)
And the blue should turn the compressor on in the other direction (IE: Hot on the water coils and cold on the fins)
YOU MUST CHECK THAT BEFORE PROCEEDING!!!

If this is not the case: with the Gray and Blue then don't proceed!!! Take meauserments on ALL wires when running in each mode, including do nothing mode, to verify!!!

But if my assumptions are correct, then connecting the gray to a hot lead (IE: jumping it to the black) "Should" jump start the unit and force it to run in cooling mode.

IF all is correct so far!!!! then in theory you could clip the gray wire from the control board and wire it to a new plug ONLY using the hot side of the plug. to jump start it..

HOWEVER if you have different circuits involved here (Not from the same wall plug) Then you "could end up with 240 instead of 120 and really fry things!!!

--------------------------------------------------

BUT I would really recommend doing this:
Disconnecting the Blue, because if for any reason your AC gave the motor power for cooling and for some reason the onboard controller called the heater. They would BOTH send a signal to the motor, causing a big problem, which may lead to a fire..

I say abandon the heater function and if the above IS true!! THen and only then just wire the black to the gray, cut the blue and tape both ends up, so it does not short out on anything..
and now when the chiller is pluged in it should cool...

ALSO I'm not responsible for any of the information above if it causes ANY undesired results including results that may end in death, a fire, injury, or a useless chiller, etc.. etc... etc...!!!

PLEASE don't attempt this if you don't know a lot about power, or feel unsafe doing it..


But from what you describe, and the way mine operates, it should work..

The weird 2.whatever volts is prolly phantom voltage with NO amperage..

[funman1]

Actually looking at the picture of the board it looks like the Gray is the heat and the Blue is the cool!?!?!?!
So if that is true then reverse my instructions above acordingly

[ShipOFools]

whats the point of doing this? do you want to to cool bellow the lowest setpoint of the temp control on the chiller? if thats the case why not replace replace the stat with one that goes down to your desierd set point?

[H20ENG]

You could always get a 2 stage Ranco controller, and let the Ranco control the chiller in both modes. Then have the AC Jr switch the Ranco only in over or under temp events like a control failure.