Bell & Gossett S11574C Heat Transfer Package with Air Separation - Manual (Page 7)

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3.7 With the disconnect switch engaged to the “ON” posi-
tion, turn selector switch to the “HAND” position
momentarily, then “OFF.” Observe the pump shaft
rotation.
3.8 If incorrect, turn the main disconnect off and inter-
change any two wire leads leaving the starter overload
block and going to the motor.
3.9 Run the pump. Take an ampere reading on the pump
motor. If it is greater than the rated nameplate full load
current, close the Triple Duty valve (turn stem clock-
wise) until the motor current decreases to the name-
plate value.
3.10 Note the value indicated by the pointer on the cali-
brated scale of the Triple Duty valve stem. Tag the
valve with this reading for future reference. The stem
is to be returned to the position at all times when the
pump is in operation, otherwise, motor overloading
may result.
3.11 TROUBLESHOOTING – ELECTRICAL
3.12 Starter overload relays must be manually reset when
tripped. To reset the overload relay press the external
reset button.
3.13 Pinpointing failures in the control circuitry largely
depends on the understanding of the circuit line dia-
gram furnished with each unit and the proper use of
test instruments. Some of the recommended test
instruments are:
a) Combination Volt-Ohm-Ammeter (VOM multi-
tester) with a 600 volt AC scale (or greater).
b) Clamp-on Ammeter (Amprobe or equal) with
ampere capacity up to 100 amps.
c) Fuse puller.
3.14 Use of “Test Light” for continuity tests is not rec-
ommended since these devices do not indicate the
actual voltage present at the test point. Locating
trouble spots with the use of “Jumper Wire” is strongly
discouraged.
3.15 Failure and Probable Causes
3.16 Motor overload relay trips.
3.17 Probable causes:
(1) High ambient temperature around panel box.
(2) Actual line voltage above or below motor name-
plate voltage limits.
(3) Overload heaters improperly selected or installed
(loose hold screw).
(4) Unbalanced voltage between phases.
(5) Faulty motor.
(6) Pump loading beyond design conditions.
3.18 Factory Service
3.19 When requesting information from the factory, it is
imperative that the following data be available for
reference.
(a) Factory Number
(b) Model Number
(c) The actual line voltage, current draw, suction, dis-
charge and system pressure, or other pertinent
information relative to the nature of the problem.
3.20 Maintenance
3.21 Lubricate motor and pump twice a year.
3.22 Repair any leaks in the hot water system immediately.
Prolonged entry of makeup water will seriously cor-
rode the piping and foul the heat exchanger.
3.23 Clean out all strainers periodically.
3.24 Be aware of ‘gurgling’ sounds through the piping sys-
tem and the pump. It may indicate an air bound
expansion tank. Bleed air from tank.
3.25 When ordering replacement parts or inquiring about
the unit, always give the complete data on the unit
nameplate as well as the component nameplate data.
DANGER: Troubleshooting live control panels
exposes personnel to hazardous voltages. Electrical
troubleshooting must only be done by a qualified electri-
cian. Failure to follow these instructions will result in
serious personal injury, death, and/or property damage.
DANGER: Troubleshooting live control panels
exposes personnel to hazardous voltages. Electrical
troubleshooting must only be done by a qualified electri-
cian. Failure to follow these instructions could result
in serious personal injury, death, and/or property
damage.
CAUTION: Prevent subsequent damage. A unit
showing symptoms of possible problems (noise,
leaks, vibration, and/or continual operation) must be cor-
rected immediately. Failure to follow these instructions
could result in property damage and/or moderate per-
sonal injury.
DANGER: High voltage 3 phase power can kill.
Disconnect and lockout power prior to servicing
unit. Failure to follow these instructions will result in
serious personal injury, death, and/or property damage.
DANGER: Troubleshooting live control panels
exposes personnel to hazardous voltages. Electrical
troubleshooting must only be done by a qualified electri-
cian. Failure to follow these instructions will result in
serious personal injury, death, and/or property damage.
CAUTION: Burn hazard. The system may contain
steam or hot water under pressure. Close the valves
to isolate the system. Drain and vent the system and allow
surfaces to reach acceptable temperatures prior to ser-
vicing. Failure to follow these instructions could re-
sult in property damage and/or moderate personal
injury.