30hxc carrier tripping on HP

[ironmen]

Hi all chiller guys.Got problem with a 30hxc carrier that continuously tripping on hp as soon as ambient temp reach 30dc.The following reading was taken yesterday.

condenser water in 24.5 dc
Condenser water out 28dc
Lp.400kpa
HP.trip at 1400kpa
On standby pressure as soon as it trip both pressure equalise to each other at 600 kpa each hp/Lp.The system run only for 15 second only.And both system is flashing as well.Is there a way to check if the exv is operating correctly.And how can i put the system on 100% capacity to check if its undercharge.Help needed guys.

[Grizzly]

Hi Ironmen.
Just a thought, Have you been able to measure the pressure drop across the condenser.
Only the TD, seems High to me!
Your HP is way high at 55c relative so I would be looking for poor flow through the condenser.
With an undercharged system I would not expect to see a hp situation.
But yes you are correct your expansion valve could be faulty and staying shut.
Also is there any way Air could of gotten into your system? ( or nitrogen!)

1 thing at a time I suppose.

Grizzly

[james10]

If EXV was faulty you would get low sst trips, as grizzly said check your water flow

[ironmen]

Hi guys.Im gonna do couple of test and i will let you khow the outcome.thanks

[goshen]

Hi james
if i remember correctly, at startup there is a delay on sst trip,
so if system trips after 15 sec ,i would go with grizzly's direction!
could be water flow,could be exv,
lets here from the ironman
good luck

[james10]

What I mean is if the EXV was faulty the unit would indeed run in overide until it timed out and
Trips on low sst, so I my mind the EXV can be ruled out unless it is completely jammed shut which I have never come across on a carrier EXV, but there is a first time for everything, also if the EXV is faulty there would more than likely be oil issues

[frank]

With a constant tripping on HP at high ambient s makes me think that the rejected heat from the condenser is not being rejected properly. What is the condenser water flow rate and what is the chiller capacity?

[Mick13]

i agree with above, sounds like a water flow issue.... maybe check strainers?

[Gibbo]

The discharge pressure is at 1400 kpa which is causing a trip on high pressure override and not hp switch.
Check the condense water side All symptoms point to lack of water flow

[goshen]

Hi
lets here from the ironman !

[ironmen]

Ok guys,here we go.pull the cooling tower apart and found about six nozzle clogged up and there was very lack of water pressure and flow going through and found the bottom filter fully blocked.so unblocked all nozzle and clean the filter and test run still trip.
And then the miracle ,temporaly bypass the plate heat exchanger and run the tower and ive never seen that tower working at full capacity,it was unbelivable.Start up the chiller and evrything was sweet as.All working perfect and both compressor working at full capacity.
condenser Inlet water temp 24.5 dc
Condenser outlet temp 31 dc
Ambient 39 dc
Hp 800 to 1000 kpa constant
Its a big relief to get that system up and runing now i need to get that plate exchanger clean out and reconnect the outlet pipe from the condenser to its original location on the exchanger.And get a proper maintenance schedule and water treatment for that system.
Thank you guys for all your support and help on that one apriciate it.

[james10]

Glad to hear you got it sorted Ironmen, always nice to hear feedback.

[goshen]

Hi
as james10 put it ,it is actully nice to get feedback,interesting too.
good luck