Bell & Gossett DN0134D Domestic Pump Vacuum Heating Units Series VLR - Manual (Page 7)

7
CONTROLS ARE PRESET A T 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 ia 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 guauge glass.
5. Adjust the cut-in point of upper compartment switch by set-
ting it for minimum level change.
FLOA T SWITCH ADJUSTMENT PROCEDURES
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
PUMP SERVICE INSTRUCTIONS FOR VACUUM PRODUCING CENTRIFUGAL PUMPS
Close coupled centrifugal pumps ar e 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 above 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
without 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 scr ews and move components to assure pressure is
relieved before r emoving scr ews. Keep drains open during
servicing. Failure to follow these instructions could result in
injury or death.
CAUTION: HOT SURFACE
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 serious injury or
death.
W ARNING: HIGH VOLTAGE
Disconnect and lock out power befor e connecting
servicing unit. Failure to follow these instructions could
result in serious injury or death.
FIG. 12