Greenheck TSU Base Unit Manual (464441) - Manual (Page 29)

Make-Up Air Unit 29
®
Evaporative Cooler does not Operate (Recirculating pump)
Supply fan must be on for cooler to operate
Troubleshooting
Water Blows through Evaporative Cooler
Water supply to great?
Use the main supply valve to reduce the supply of water
Air velocity greater than
specified?
Reduce the air velocity through the media
(Reference Blower Start-Up – Step 5)
At this time the evaporative cooler should be
operating without water blowing through
Are the headers in place and
located near the entering
air side of the media? Replace headers and/or move the headers
(Reference Evaporative Cooling Recirculating Start-Up – Step 1)
Yes
No
Yes
Yes
No
No
115 VAC between terminals
102 and 101
24 VAC between terminal A2 on
Cooling Relay (RC) and X
Cooling transformer (TR4) defective
(Replace transformer)
External 115 VAC power supply to terminals
102 and 101 not connected
(Connect power supply)
Optional inlet air sensor (TS4) holding
(Adjust TS4 setting. Reference Blower Start-Up – Step 6)
115 VAC between terminal
114 and 101 Cooling relay (RC) is not energized
(Check for loose connections)
(Repair or replace relay)
24 VAC between terminals
Y1 and X
Cool switch (S4) off
(Turn cool switch (S4) on)
Cool switch not wired
(Wire cool switch (S4))
No
No
No
Yes
Yes
Yes
At this time the evaporative cooler pumps should be on
Yes