73
VIII.
VIII.
Troubleshooting
Troubleshooting
Circulation Pump
Circulation Pump
-
-
Water Switch Pump Nuisance Tripping (1)
Water Switch Pump Nuisance Tripping (1)
There have been some nuisance tripping of thermal motor protectors on
three-winding circulation pumps for use with water switches (#
239129
).
To prevent nuisance tripping, use pumps with upgraded thermal
protectors (#
437345
). If upgraded pumps (#
437345
) aren’t available,
use original circulation pumps (#
239129
) with new (PTC) motor starters
designed to prevent nuisance tripping (#
423023
).
IMPORTANT:
Using new & original
pumps & motor starters:
•
Use “new" circulation pump #
437345 (with 135ºC OVLP) only
with "original" motor starter #
182318 (4.7 – 4.8
Ω
).
•
Use “original" circulation pump #
239129 (with 120ºC OVLP) only
with "new" motor starter # 423023
(15
Ω
).
TECH NOTES:
New motor starter # 423023 (15
Ω
) has a larger resistance to limit current
draw through pump motor start windings. Winding temperatures are reduced, but starting
torque is reduced as well. So, new motor starters (# 423023) should never be used with new
circulation pumps (# 437345).
HINTS:
Typical repairs will involve either replacing “original" circulation pump # 239129 with
“new" circulation pump # 437345 (preferred) or replacing "original" motor starter # 182318
with "new" motor starter # 423023.
TECH TIPS:
All circulation pump motors use auto-reset thermal protectors. Once motor
windings cool below a preset temperature, protectors reset and pumps will work again. If
thermal protectors fail to reset, replace pumps.