View Full Version : CIAT LXH 1850Z-HPS, intermittent HP1 fault.

30-06-2015, 08:48 PM
Scratching head.

getting hp fault on above 407c chiller, sometimes it will run for a day
(HP225 LP55 sup.h around 7k 3ish water TD).
Other times it will go in to fault before the contacts have even pulled in. To my knowledge I have checked all the components on the circuit that may throw up this fault, cant find any loose connections..

Has any body had this issue before, or can offer any advice. ANY welcome please.


The Viking
30-06-2015, 11:11 PM
This is a blend that not is very stable, if you reclaim all the gas from the system in to a single (clean) reclaim bottle then first of all you can verify that the charge is correct but you will by this procedure also remix the R407c (providing that you recharge it in liquid state).

Another thing you didn't mention, well two actually, sub cooling and actual water temperatures...

Happy hunting.


30-06-2015, 11:32 PM
Has condenser cooling water circuit been checked out.
Master filters, flow switch?

01-07-2015, 07:57 PM
Air on +22
Air off +45
Water on +15
Water off +12
Sub C 12k before economiser

What's troubling me is that it trips on HP (not pressostat) before the contactors have even pulled in. Some thing else in that leg is causing the fault but I can't see on the wiring diagram what else is on the leg of controls as its a pcb

01-07-2015, 07:58 PM
Air cooled mate, all fans operational.

02-07-2015, 05:31 PM
Is there a hp transducer as well as the mechanical one or something else wired in series

03-07-2015, 07:35 AM
There is a pressostat and a transducer, the pressostat isn't tripping.

03-07-2015, 08:21 AM
Could be a faulty transducer check what the hp setting is on the controller

03-07-2015, 07:44 PM
First of all thanks for all your input.
Found it to be the first part winding contactor not pulling in/dropping out intermittently, HP circuit runs through the contactor auxiliary. I got carried away looking for something complicated. Always feels like you should have found it sooner once you've found it.


03-07-2015, 08:01 PM
Back on site today. Faulty contactor on first part winding, dropping out/not pulling in intermittently, HP circuit runs through contactor auxiliary.

Thanks for all the input chaps