5
3.0
PUTTING THE UNIT INTO SERVICE
GMU30 is designed for systems requiring up to
30-psi, drawing water or water-glycol mixture up to
10-gpm from the 55-gallon tank and automatically
servicing the closed-loop system.
GMU60 is designed for systems requiring up to
60-psi, drawing water or water-glycol mixture up to
5-gpm from the 55-gallon tank and automatically ser-
vicing the closed-loop system.
When pressure in the closed-loop system decreases
to the cut-in pressure the pump will start. The pump
runs until the pressure switch reaches the cut-out
pressure. The pressure switch factory default cut-in
setting for GMU-30 is 5-psi, and the cut-out setting
is 21-psi. The pressure switch factory default cut-in
setting for GMU-60 is 30-psi, and cut-out setting is
50-psi.
3.1
ADJUSTMENTS AND SETTINGS
3.1.1
Pressure Switch
Electrical equipment should be serviced only by qual-
ified electrical maintenance personnel.
The pressure switch is piped to the discharge line.
There are two adjusting screws located on the top of
the switch control. This adjustment must be made
before operating the system.
Adjust pressure switch as follows:
a) Cut-In (Turn nut clockwise for higher pressure or
counterclockwise for lower pressure).
b) Cut-Out (Turn nut clockwise for higher pressure or
counterclockwise for lower pressure).
c) Check switch operation after resetting.
d) See above picture for adjustment nut locations.
3.1.2
Triple Duty Valve
The Triple Duty Valve is piped to the discharge of the
pump and is used as a non-slam check valve, cali-
brated balance valve and shutoff valve for this unit.
The valve stem is located on the top of the valve. The
Triple Duty Valve has a calibrated nameplate on the
valve stem for rough system balance and position
indication. Prior to placing GMU into operation,
installer must adjust the Triple Duty Valve.
3.1.2.1 Adjust Triple Duty Valve
a) Never turn the valve stem in excess of 100% open
when system is pressured. At this position the
valve does not act as a check valve. It is a gravity
flow valve.
b) Never turn the valve stem to the closed position
when operating the system. This position provides
positive shutoff.
c) Adjust the valve between 20% to100% open.
3.1.3
Diaphragm Expansion Tank
Diaphragm expansion tank factory pre-charge is 40-psi.
Adjust pre-charge to equal incoming pressure. Refer
to the specific IOM #V58303 that was shipped with
the tank for installation and operating instructions.
3.1.4
Low Water Cut Off Switch
When the water or water-glycol mixture in the 55-gallon
reservoir falls below the low level point, the low water
cut-off switch will turn the pump off. An alarm light
will illuminate.
3.1.5
Sequence of Operation
When pressure in the system decreases to the mini-
mum allowable fill pressure, the pressure reducing
valve opens.
The Glycol stored in the pressure tank flows to the
system, when pressure supplied to the pressure
reducing valve reaches the pump cut-in pressure, the
GMU pump will start.
Pump runs until pressure switch reaches the cut-out
pressure.
Should the Glycol solution in the 55-gallon reservoir
fall below the low level point in the reservoir, the low
level switch will turn pump off, an alarm light will be
signaled.
Section 3
WARNING: Electrical shock hazard. Single phase
or three phase AC power. Disconnect and lockout
power before servicing unit. FAILURE TO FOLLOW THESE
INSTRUCTIONS COULD RESULT IN SERIOUS PER-
SONAL INJURY, DEATH, AND/OR PROPERTY DAMAGE.
CAUTION: Prevent subsequent damage. A unit show-
ing symptoms of possible problems (noise, leaks,
vibration, and/or continual operation) must be corrected
immediately. FAILURE TO FOLLOW THESE INSTRUC-
TIONS COULD RESULT IN PROPERTY DAMAGE
AND/OR MODERATE PERSONAL INJURY.
Adjust for cut-in point
Adjust for cut-out
PRESSURE SWITCH
WARNING: Electrical shock hazard. Disconnect and
lockout power before servicing the unit. FAILURE TO
FOLLOW THESE INSTRUCTIONS COULD RESULT IN
SERIOUS PERSONAL INJURY, DEATH, AND/OR PROP-
ERTY DAMAGE.
WARNING: Setting the Triple Duty Valve in excess of
100% open within the range labeled gravity flow can
allow backward flow of glycol into the 55-gallon tank and
overfill it. Adjustment must be made before placing the unit
into operation. Follow the instructions that are supplied with
the unit. FAILURE TO FOLLOW THESE INSTRUCTIONS
COULD RESULT IN PROPERTY DAMAGE AND/OR
MODERATE PERSONAL INJURY.
