Bell & Gossett S14141B 70X Multiple Pump Pressure Booster Systems - Manual (Page 7)

2.12 DIFFERENTIAL PRESSURE SWITCH
PIPING AND WIRING
2.12.1 (Optional) Differential pressure switches are avail-
able to sense the increase in pressure between
the pump suction and discharge gauge taps that
is used to determine whether a pump is running.
The switch is wired normally closed to the control
panel. Refer to wiring diagram for exact terminal
locations. (Differential pressure switch may
require field calibration.) Ref-3.6.1.
2.13 LOW SUCTION PRESSURE
2.13.1 (Optional) Low suction pressure switch is avail-
able and intended to stop pump operation when
an insufficient pump suction condition exists. The
switch is wired normally closed to the control
panel. Refer to wiring diagram for exact terminal
locations.
SECTION 3 - START UP
3.1 PUTTING THE UNIT INTO SERVICE
3.1.1 After package is installed and foundation bolts
are tightened, check pump alignment. Refer to
specific pump Installation, Operation &
Maintenance manual for alignment procedures.
3.1.2 Fill system with fluid after reading the cautions in
the piping connection section of this manual.
3.1.3 Vent all high points in the piping system to
removed trapped air.
3.1.4 Before starting all pumps and drivers should be
checked for proper lubrication.
3.1.5 Piping should be clean and flushed prior to
operation.
3.1.6 PUMP ROTATION, 3 PHASE MOTORS ONLY
3.1.7 With the disconnect switch engaged to the "ON"
position, momentarily start and stop each motor.
Observe the pump shaft rotation.
3.1.8 If incorrect, turn the main disconnect off and inter-
change any two wire leads leaving the starter over-
load block and going to the motor.
3.1.9 Unit is now ready for operation.
3.2 ADJUSTMENTS
3.2.1 Final adjustments on the following adjustable
devices shall be made to match exact system
requirements.
3.3 THERMAL RELIEF VALVE
3.3.1 A thermal relief valve is installed on the discharge
header to prevent potentially dangerous thermal
pressure buildup. The valve automatically opens
on temperature increase and closes on tempera-
ture decrease. This valve acts as a safety device
and should never be removed or plugged. It is fac-
tory set to open and discharge when the water
temperature in the discharge header reaches
125°F. The 3/8" NPT opening of this valve shall be
piped to a floor drain in accordance with local codes.
3.3.2 To raise the valve opening point, turn the adjust-
ment screw counter-clockwise; to lower the valve
opening point, turn the screw clockwise. The clos-
ing point is non adjustable, approximately 3 to 5º F
below opening point.
3.3.3 To flush valve manually, insert a screwdriver under
each side of the lower spring guide. Pry both guide
and spring away from body to open valve.
3.3.4 After long periods of operation, valve seat and disc
may become worn or pitted, allowing leakage
through valve in closed position. Internal parts can
be replace if desired.
3.4 PRESSURE REDUCING VALVE (PRV)
3.4.1 The PRV is used to maintain a desirable pressure
at the discharge header. The PRV is preset at the
factory to the exact system requirements. If fur-
ther adjustments are necessary refer to the PRV
instruction manual.
3.5 High PRESSURE PRV (If Required)
3.5.1 On systems where the system pressure reaches
above 135 psi a high pressure PRV is required to
protect the thermal relief valve from exceeding its
pressure rating. The high pressure PRV has an
adjustable range from 30 to 300 psi and is manu-
facturer set at 60 psi. No further adjustments are
recommended.
3.6 DIFFERENTIAL PRESSURE SWITCH (Optional)
3.6.1 The differential pressure switch has a range from
1/2-36 psid and is manufacturer set at 18 psid. It is
recommended that the setting be adjusted to 2 psi
less than the minimum pump differential pressure
to avoid nuisance alarms. The minimum pump dif-
ferential pressure is equal to the pump discharge
pressure at minimum speed minus suction pres-
sure. To adjust the setting, remove the cover. To
decrease the operating point, face the switch,
place a flat bladed screwdriver in the slots of the
main range adjustment nut and rotate from left to
right. For further information refer to switch
instruction manual supplied with the unit.
3.7 LOW SUCTION PRESSURE SWITCH (Optional)
3.7.1 Manufacturer set at 40 psi. It is recommended that
the setting be adjusted to 10 psi below rated suc-
tion pressure. To adjust the setting, remove the
cover. Turn the reference dial to the desired set
point by aligning setting on dial with the dowel pin.
WARNING: Rotating shafts can catch loose clothing.
Do not operate the pump without all guards in place.
FAILURE TO FOLLOW THESE INSTRUCTIONS COULD
RESULT IN SERIOUS PERSONAL INJURY, DEATH,
AND/OR PROPERTY DAMAGE.
DANGER: High Voltage 3 phase power can kill.
Disconnect and lockout power prior to servicing unit.
FAILURE TO FOLLOW THESE INSTRUCTIONS COULD
RESULT IN SERIOUS PERSONAL INJURY, DEATH,
AND/OR PROPERTY DAMAGE.
CAUTION: Seal Damage may occur. Do not run
pumps dry. Fill and vent the pump volute prior to
operation.
FAILURE TO FOLLOW THESE INSTRUCTIONS COULD
RESULT IN PROPERTY DAMAGE AND/OR MODERATE
PERSONAL INJURY.
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