Bell & Gossett DN0156F HS Vented Condensate Units Watchman Series SCC - Manual (Page 6)

6
These close coupled vertical centrifugal pumps are equipped
with mechanical seals. If system has not been properly cleaned
prior to installation of pump, foreign matter such as dirt, pipe
scale, core sand, etc. may clog the impeller and damage the
seal. A strainer is recommended in return line to pump.
Pump
must not be operated dry. Seals may be damaged if operated
without water present.
1. Close inlet line gate valve and operate pump momentarily
to remove as much liquid as possible from pump. Close
discharge line gate valve.
2. Shut-off and lock out power.
3. Disconnect wiring to motor.
4. Make sure unit is cool enough that pump can be handled
safely. Open receiver drain to remove remaining liquid.
5. Loosen the motor to pump volute fasteners. Assure that
pressure is relieved per caution note.
6. Remove four capscrews (7) holding volute to motor and lift
motor and impeller out of pump volute.
7. Remove pump/motor assembly and place on work bench.
8. Hold top end of motor shaft with large screwdriver via
screwdriver slot in shaft and back off impeller (counter-
clockwise) with a rectangular bar or other flat tool inserted
between vanes of the impeller.
9. Remove the rotating part of the mechanical seal from the
end of the shaft.
10. Remove seal holder (2) with stationary ceramic part of
mechanical seal cup rubber from the end of the shaft.
11. Remove stationary ceramic part of mechanical seal and
cup rubber from recess in seal holder.
12. To install new seal proceed as follows: Clean recess in seal
holder thoroughly. Orient motor so that conduit opening on
motor is to the left when looking at motor shaft. Replace
seal holder on the face of the motor maintaining concen-
tricity with motor face. Place new ceramic part of seal in
the cup rubber over motor shaft and press firmly into
recess of seal holder by hand, making certain both parts
bottom evenly. If assembly cannot be bottomed with fin-
gers place a wooden or cardboard tube over shaft onto
ceramic and push into place. Using a clean lint-free cloth,
wipe the mating surfaces of the seal clean of any foreign
matter. Moisten the carbon section of the rotating part of
the seal and place onto the shaft to seat against ceramic.
Place seal spring onto shaft.
13. Hold motor shaft as described in #4 and replace the
impeller on the shaft (clockwise rotation) making sure it is
tight.
14. Orient motor for pump reassembly with conduit opening to
the left. When mounting pump case, discharge should be
90º to the right of the conduit opening on motor. Use care
to insure tight gasket fit to prevent water leakage.
15. Replace four capscrews (7). Tighten down capscrews
evenly to avoid damage.
16. Reconnect pump bleed line (where applicable) and motor
wiring.
17. Close drain and slowly open inlet valves. See warning.
18. Jog to check motor rotation. See caution.
19. Observe operation thru several cycles.
PUMP SER VICE INSTRUCTIONS FOR WATCHMAN “B” DESIGN CENTRIFUGAL PUMPS
CAUTION: HOT SURFACES
Surfaces ar e hot when system is in operation. Do not
touch hot receiver, let unit cool before servicing. Failure to
follow these instructions could result in injury or property
damage.
W ARNING: HIGH VOLTAGE
Disconnect and lock out power befor e connecting or
servicing unit. Failure to follow these instructions could
result in serious injury or death.
CAUTION: PRESSURIZED SYSTEM
Operating system may contain very hot water under
pressure. Close inlet and open drains before servicing.
When servicing,
loosen scr ews and move components to
assure pressure is relieved before r emoving scr ews. Keep
drains open during servicing. Failure to follow these instruc-
tions could result in injury or property damage.
CAUTION: DO NOT RUN DRY.
SEAL DAMAGE MAY OCCUR.
Inspect pump seal r egularly for leaks. Replace as required.
Failure to follow these instructions could result in injury or
property damage.
W ARNING: EXPLOSIBLE
Do not pr essurize receiver. Isolate receiver during leak
test. Do not plug overflow. Do not restrict vent opening to
atmosphere. Open valves slowly. Failure to follow these
instructions could result in serious injury or death.
CAUTION: DO NOT REVERSE
Reverse operation can cause extensive damage to
pumps. Jog the motor to test for direction of rotation. Failure
to follow these instructions could result in injury or property
damage.