Bell & Gossett DN0153D HS Vacuum Heating Units Series HV - Manual (Page 7)

(3) Place motor vertically with pump end up. Do not
attempt assembly of seal and impeller with shaft
horizontal.
(4) The “carbon” of rotating part of seal should not be
loose. If it is, hold in place with grease, Using clean, lint
free cloth, wipe mating surfaces perfectly clean. Soap
shaft and push seal onto shaft so that carbon will con-
tact ceramic seal. If spacer is required, use grease to
cause spacer to adhere to bottom of seal after seal has
been put on shaft, Be sure spacer is on larger diameter
of shaft so that will not catch between shoulder and
impeller.
13. Replace impeller on shaft. Replace stainless steel washer
and secure impeller with capscrew or cap nut.
14. Place new gasket on pump volute and reassemble motor
and pump subassembly on pump volute.
15. Reconnect pump bleed line and motor wiring.
16. Close drain and slowly open inlet valves. See warning.
17. Jog to check motor rotation. See caution.
18. Observe operation thru several cycles.
WARNING: EXPLOSIBLE
Do not pressurize 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 serious
injury or death.
WATER
SLINGER
VIEW OF
THREADED
IMPELLER
WEAR RING
IMPELLER
2DPF03
VOLUTE
MOTOR BRACKET
MECHANICAL
SEAL
CAUTION: DO NOT RUN DRY.
SEAL DAMAGE MAY OCCUR
Inspect pump seal regularly for leaks Replace as required.
Failure to follow these instructions could result in serious
injury or death.
8
TROUBLESHOOTING SERIES HV UNITS
ALL UNITS ARE THOROUGHLY TESTED AT THE FACTORY BEFORE SHIPMENT AND SHOULD OPERATE SATISFACTORILY
WITHOUT FURTHER ADJUSTMENT IF PROPERLY INSTALLED AND IF NOT DAMAGED BY ROUGH HANDLING IN
TRANSIT. IF SYSTEM OR UNIT PERFORMANCE IS NOT SATISFACTORY, REFER TO THE FOLLOWING CHECK LIST.
PUMP WILL NOT START
1. The power supply has been interrupted, disconnect switch
is open or selector switches improperly positioned.
2. Insufficient condensate has accumulated to actuate float
switch.
3. Vacuum is not low enough to actuate vacuum switch.
4. Incorrect voltage for motor. Check voltage and wiring with
motor characteristics.
5. Incorrect starter coil for power supply.
6. The overload relays in the starter have tripped out and
must be reset. Ambient temperature may be too high.
7. Check float switch, vacuum switch or other control for
proper operation.
8. Wiring to control panel is incorrect or connections are
loose.
PUMP DOES NOT RETURN ALL CONDENSATE TO
BOILER FEED SYSTEM (SYSTEM FLOODS)
1. Pump is running backward looking down on motor.
Rotation of 3 phase motors may be corrected by inter-
changing any two of the three wires. Pump should run
clockwise.
2. Steam traps are blowing through causing condensate to
return at excessive temperatures. If 160°F is exceeded the
capacity of the pump may be reduced below its rating.
Traps should be repaired or replaced.
3. The total pressure at the pump discharge is greater than
the pressure for which the pump was designed. Check the
total pressure which includes the boiler pressure, the fric-
tion head and the static head.
4. A valve in the discharge line between pump and boiler is
closed or throttled too tightly. Check valve is installed
backwards.
5. Condensate is held up in system periodically by induced
vacuum in boiler or radiation then released in a flood when
the pump starts. Install equalizer line.
6. The strainer is dirty thus retarding flow. Refer to instruc-
tions for cleaning.
7. The impeller eye is clogged with trash. Clean.
8. The bellows type discharge valve fails to open. This may
be caused by the solenoid valve remaining in a closed
position, or dirt becoming lodged in the pressure release
line. Float switch failure may also cause the discharge
valve to remain shut. Replace the bellows type discharge
with the solenoid operated discharge valve. If solenoid dis-
charge valve has already been installed the solenoid may
be stuck shut or the float switch failed.
9. Systems with accumulator tanks should have equalizer
line run from accumulator tank to steam header NOT
from accumulator tank to pump receiver NOR from pump
receiver to steam header. Install vacuum breaker on
accumulator tank, NOT on pump.
10. Pump is too small for the system.
CONTROLS ARE PRESET AT THE FACTORY BUT
MAY VARY DUE TO HANDLING DURING SHIPMENT.
PROPER ADJUSTMENT OF CONTROLS
ASSURES BEST PERFORMANCE.
1. Close the inlet gate valve and operate the pump on CON-
TINUOUS to remove as much water as possible from the
receiver. Open disconnect switch(es).
2. Adjust cut-off point of lower compartment float switch so
that switch opens just before float touches bottom of
receiver. Both switches of duplex units should open at
same low level. (See switch manufacturer’s instructions for
procedure).
3a. (One float switch in lower compartment.) Remove strainer
cover and fill lower compartment thru strainer. Close inlet
valve and remove drain plug from strainer. When water
stops flowing from drain opening adjust cut-in point of
lower float switch by depressing float arm slightly and set-
ting adjusting strip so that switch turns on when float arm
is released.
3b.(Two float switches in lower compartment.) Adjust cut-in
point of second switch so that operating range is approxi-
mately 2 divisions narrower than range for switch adjusted
in 3a.
4. Adjust cut-off point of upper compartment float switch so
that switch opens when there is about 1 / 4 " water in gauge
glass. Check as follows: (1) close discharge gate valve,
(2) fill top compartment until upper float switch closes,
(3) close inlet valve, (4) set selector switch on FLOAT
ONLY, (5) open discharge gate valve. When float switch
opens and pump stops, level should be
1 / 4 " in gauge glass.
5. Adjust the cut-in point of the upper compartment switch by
setting it for minimum level change.
FLOA T SWITCH ADJUSTMENT PROCEDURES
7
HIGH LEVEL
FLOAT SWITCH-ON
WATER LEVEL
GAUGE
INLET
1 / 4 "
HIGH LEVEL
FLOAT SWITCH -ON
LOW LEVEL
FLOAT SWITCH -OFF
VENTURI
LOW LEVEL
FLOAT SWITCH-OFF
FIG. 12
PUMP SERVICE INSTRUCTIONS FOR VACUUM PRODUCING CENTRIFUGAL PUMPS
Close coupled centrifugal pumps are designed for years of
trouble free service. Units have mechanical shaft seals and are
vertically mounted to put the motor above floor dirt and water.
1. Drain hurling chamber.
2. Shut-off and lock out power.
3. Make sure unit is cool enough that pump can be handled
safely. Open drain to remove remaining liquid.
4. Carefully remove pump drain plug and bleed line. Wait for
complete drainage.
5. Loosen the motor bracket to pump volute capscrews.
Assure that the pressure is relieved per caution note.
6. Complete the removal of the hardware. Remove pump/
motor assembly and place on work bench.
7. Remove self locking stainless steel capscrews and stain-
less steel washer (or self locking brass cap nut and
washer) that secure the impeller in place.
8. To remove impeller from motor shaft proceed as follows:
(1) Keyed Shafts. Remove impeller with gear puller or other
means which will not damage impeller or bend motor
shaft.
(2) Threaded Shafts. Hold end of motor shaft opposite
pump with large screwdriver or other suitable tool and
back impeller off with a rectangular bar or other flat tool
inserted between the vanes of the impeller.
9. Remove rotating part of seal from shaft, being careful not
break carbon face.
10. Remove capscrews holding motor bracket to motor and
remove bracket.
11. Remove stationary part of seal assembly, being careful not
to chip or break ceramic seal.
12. To install seal proceed as follows:
(1) Clean recess in bracket thoroughly. Coat recess and
“rubber” portion of seat with soap solution. Press seat
into recess firmly by hand making certain both parts
bottom evenly. If seal cannot be bottomed with fingers
place cardboard shipping disc on ceramic and force
into place with tool.
(2) Carefully place bracket in position on motor shaft with-
out displacing ceramic seat and secure bracket to
motor with capscrews.
CAUTION: PRESSURIZED SYSTEM
Operating system may contain very hot water. Close
inlet and open drains before servicing. When servicing,
loosen screws and move components to assure pressure is
relieved before removing screws. Keep drains open during
servicing. Failure to follow these instructions could result in
injury or death.
CAUTION: HOT SURFACE
Surfaces are hot when system is in operation. Do not
touch hot receiver, let unit cool before servicing. Failure to
follow these instructions could result in serious injury or
death.
WARNING: HIGH VOLTAGE
Disconnect and lock out power before connecting
servicing unit. Failure to follow these instructions could
result in serious injury or death.