Latte
28-07-2005, 08:50 PM
Hi Guys,
Sorry, This is likely to be a long thread but i got called out to my first water cooled unit with problems and i am now :confused: .
First, what i do know:-. The AHU is made by "Air Handlers (Leicestershire) Ltd. but the phone number on the plates is no longer in use. The unit is controlled by 3 touch screens, one in the boiler room which i think is more of a moniter, one in the plantroom which is the controller and one on the side of the pack. The controllers have Electrotech control design services plastered all over them.
Now the problem, the unit will not get below 24 degree's.
First problem i found was the cold water pump on the side of the pack had tripped. I reset this and checked it and assumed over time it would pull back down - WRONG !!!:eek:
Had another look today, pump OK, cold water showing 9 degrees but when i looked at the AHU it appears to me that the reheat valve is letting by. The control side appears to be OK. The valves are controlled by Trend actuators which have a plunger going into the valves. Now at the moment the reheat valve has the plunger all the way up (Shut) and the cooling valve has the plunger all the way down (Open). Now feeling all three pipes on both, they are the same temp so am assuming they are bypassing and i am getting both the cool and heat coils inside the AHU working against each other.
Now, hear goes, The valve on the top of each valve is a Trend V50/P/26 but the valves have no markings as to manufacturer.
The cooling valve has stamped into the body 1 1/2" PN16 B G25 and the reheat Valve as stamped on it 1" PN16 B G25.
Does anybody know what make these valves are as a need to get some. Secondly, Changing them doesn't look too bad as there are shut off valves on all three pipes on them both but i assume i need to shut the pumps off. The cooling side i already know the pump is beside the pack but the heating pump i havn't found yet, any idea's what i am looking for.
Well i think thats it, too many questions, too stubby fingers to keep typing
Regards
Fatboy
Sorry, This is likely to be a long thread but i got called out to my first water cooled unit with problems and i am now :confused: .
First, what i do know:-. The AHU is made by "Air Handlers (Leicestershire) Ltd. but the phone number on the plates is no longer in use. The unit is controlled by 3 touch screens, one in the boiler room which i think is more of a moniter, one in the plantroom which is the controller and one on the side of the pack. The controllers have Electrotech control design services plastered all over them.
Now the problem, the unit will not get below 24 degree's.
First problem i found was the cold water pump on the side of the pack had tripped. I reset this and checked it and assumed over time it would pull back down - WRONG !!!:eek:
Had another look today, pump OK, cold water showing 9 degrees but when i looked at the AHU it appears to me that the reheat valve is letting by. The control side appears to be OK. The valves are controlled by Trend actuators which have a plunger going into the valves. Now at the moment the reheat valve has the plunger all the way up (Shut) and the cooling valve has the plunger all the way down (Open). Now feeling all three pipes on both, they are the same temp so am assuming they are bypassing and i am getting both the cool and heat coils inside the AHU working against each other.
Now, hear goes, The valve on the top of each valve is a Trend V50/P/26 but the valves have no markings as to manufacturer.
The cooling valve has stamped into the body 1 1/2" PN16 B G25 and the reheat Valve as stamped on it 1" PN16 B G25.
Does anybody know what make these valves are as a need to get some. Secondly, Changing them doesn't look too bad as there are shut off valves on all three pipes on them both but i assume i need to shut the pumps off. The cooling side i already know the pump is beside the pack but the heating pump i havn't found yet, any idea's what i am looking for.
Well i think thats it, too many questions, too stubby fingers to keep typing
Regards
Fatboy