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dumbmechanic
23-11-2009, 05:09 AM
hi all,
has anybody ever worked on a pgc climate lab environmental chamber? i realy nead some help
trouble shooting this one.

temp set for 60c
RH set for 90 to 95%
temp only reaches 55c at best
RH is ok 90-95

hot gas bypass all open
water heater full power on
air heat --- nothing?

mad fridgie
23-11-2009, 05:15 AM
hi all,
has anybody ever worked on a pgc climate lab environmental chamber? i realy nead some help
trouble shooting this one.

temp set for 60c
RH set for 90 to 95%
temp only reaches 55c at best
RH is ok 90-95

hot gas bypass all open
water heater full power on
air heat --- nothing?
I see you are in the US are you really talking about C or do mean F, if you are talking about C turn off the the refrigeration!

dumbmechanic
23-11-2009, 05:34 AM
yes celsius. thank you. it may be posible that the hot gas is over loading the heaters. i will look into that. have you ever adjusted the proportional band on one of these?

dumbmechanic
23-11-2009, 05:37 AM
watlow control
micro pro-1000
mdl# 93-00-03

mad fridgie
23-11-2009, 05:43 AM
Never seen one in my Life, but have designed many (but I have come up from the tools back ground)
The refrigerant is removing your heat
I presume that the refrigeration is controlled by a humidity controller and the temp is controlled by the heater via some sort of electronic relay/PID controller. It sounds as if this working out of specification.
To me without knowing the machine I would a temp limit on when the refrigeration runs.
When you mean water heater, do you mean a steam bath, or a closed loop water heater.

dumbmechanic
23-11-2009, 06:04 AM
thank you again your advise is greatly appriciated.
heating and cooling coils are emersed in water heat exchanger directly in water line going to spray nozzles

dumbmechanic
23-11-2009, 06:06 AM
i dont think this would be a closed loop.
the heaters are in line with the water entering chamber

dumbmechanic
23-11-2009, 06:09 AM
wich leads me to think that this heating and cooling cirquit is ok since the relative humidity is in spec.

dumbmechanic
23-11-2009, 06:14 AM
what iam now focused on is the air heaters
i have no power to these. the traic is good. the control board powering these heaters was swapped with the control board for the water cirquit.

still nothing.

mad fridgie
23-11-2009, 08:04 AM
Know we are going down he right track, (sorry I can not help with specifics)
So from what you have said the problem lies with the power board driver, Have you check all temperature probes (if these are faulty or have moisture damage they can give the impression (to the controller) that the correct temperature has been reached.
Apart from that it becomes very product dependent!!!!!!

dumbmechanic
24-11-2009, 03:29 AM
i checked the probes today- all okay. determined the cause to be with the main power control board. its time to retire the 1985 wattlow 1000. i will be upgrading this one to the 21st century. any sugestions on a reliable control?
thanks for your help.

mad fridgie
24-11-2009, 06:25 AM
In the past I used PLCs, "AB", or Shimiden out of Japan.
There must be plenty of good gear in the States.
Is it $ driven? If not go for industrial quality, if price driven Carell seem OK