Hale MG - Manual (Page 30)

Muscle Pumps
1-23
Thermal Relief Valve (TRV)
An optional Thermal Relief Valve (TRV), figure 1-
21, can be attached to the main pump body. This
valve prevents the overheating of the pump under
certain operating conditions. The valve monitors
and controls the temperature of the water in the
pump. When the temperature exceeds 120°F, the
valve automatically opens and discharges a small
amount of water either to the ground or into the
water tank, allowing cooler water to enter the
pump. After the temperature reduces to a safe
level, the valve closes until the temperature is
exceeded again.
The TRV-L model includes a chrome panel
placard with warning lamp and lamp test button,
and a preassembled wiring harness. The light
illuminates whenever the TRV is open and
discharging water. An optional buzzer provides
audible warning. The buzzer mounts in a 1-1/8
inch opening on pump panel.
Figure 1-21. Thermal Relief Valve (With Light Kit Installed)
FITTING-1/8 NPT X 1/8 FNPT
ELBOW-1/8 NPT X 1/4 FNPT
REDUCING STREET
PRESSURE SWITCH
TO CHASSIS GROUND
INSTALLER SUPPLIED WIRE
(14 GA. SXL OR GXL SAE J1128)
TO CHASSIS GROUND
POWER CONNECTION
THRU 10 AMP 12V FUSE
ALARM-AUDIBLE
INSTALLER SUPPLIED WIRING
FOR AUDIBLE ALARM OPTION ONLY.
(14 GA. SXL OR GXL SAE J1128)
BODY-INDICATOR LIGHT
BULB LENS
SWITCH-PUSH BUTTON
NAME PLATE, TEST
SWITCH, AND LIGHT
CONNECTION FOR
RELIEF VALVE
DISCHARGE LINE
WIRING HARNESS
TRV