Bell & Gossett DN0135D Domestic Pump Vacuum Heating Units Series VL - Manual (Page 6)

6
OPERA TION AND MAINTENANCE
Operators must be familiar with all sections of this manual to
understand the operation of the unit.
Hot water, steam and electricity can be hazardous.
Check motor nameplate for any lubrication requirements.
Pumps require no lubrication.
NOTICE/AUTO REST ART
Single phase motors will r estart automatically after thermal
overload protector trips.
Overload thermal relays in starters must be reset manually.
A properly installed unit should function unattended for long
periods of time. Periodic checks to assure proper operation are
highly recommended. Refer to trouble shooting section when
necessary.
Frequent starting and stopping of the pumps (short cycling) is
a symptom of system problems and will lead to premature
failure of the vacuum producer. See Trouble Shooting procedures.
A variety of control options are available and are furnished in
accordance with user specifications. Refer to wiring diagrams
(when furnished) to determine control switch settings.
The inlet strainer (when furnished) is intended to protect the
pump and system. Periodic cleaning should be included in the
maintenance schedule. Check frequently in new systems.
GAGE GLASS MAINTENANCE (Vented Systems)
Clean gage glass as r equired using commercial glass cleaner.
Dilute muratic acid may be used if required (observe handling
precautions). Never clean gage glass with wire brushes,
scrapers or harsh abrasives.
Do not reuse gage glass or packing or seals.
Immediately replace glass which is broken, cracked, chipped,
scratched or otherwise damaged. Inspect periodically with a
bright concentrated light. Anything which glistens and catches
the fingernail or any star-shaped or crescent-shaped mark
which glistens is cause for replacement. Any gage glass which
appears cloudy or roughened and will not respond to cleaning
procedures should be replaced.
When replacing gage glass, use new packings specified for this
use. Install glass with sufficient end clearance for expansion
(keep glass to metal clearance at each end) and tighten nuts
just enough to avoid leakage (do not over tighten).
Condensate enters the screen from the bottom and flows
outward from the inside. Foreign matter intercepted by the
screen may drop into the large dirt pocket in the lower portion
of the strainer body; however, grease, oil, gasket material and
other foreign substances present in all heating systems are
likely to stick and clog the strainer screen. For this reason it
may be necessary to clean the strainer several times a week
during the first few months of operation.
To clean strainer proceed as follows: (1) open disconnect
switch(es), (2) close return line gate valve, (3) remove drain
plug, (4) remove cap screws, cover and screen, (5) clean screen
thoroughly, (6) flush strainer body and dirt pocket, (7) inspect
gasket, (8) reassemble.
While the pump is shut down inspect and clean the multi-jet
nozzles as follows: (1) drain receiver below nozzle level by
removing drain plug, (2) remove discharge manifold cover plate
and multi-jet nozzle, (3) clean nozzle, (4) inspect gasket and
reassemble, (5) reprime pump to half way level in gauge glass,
(6) close switches, (7) open return line gate valve slowly.
INLET BASKET STRAINER MAINTENANCE
WARNING: 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: SUBSEQUENT DAMAGE
A unit showing symptoms of possible pr
oblems (over-
flow, noise, leaks, vibrations, continual operation, etc.) must
be corrected immediately. Failure to follow these instructions
may result in full liability for subsequent injury or property
damage. SAFETY INSTRUCTIONS
SEE COVER OF THIS MANUAL
VACUUM GAUGE TAPPING
VACUUM BREAKER TAPPING
CAPSCREWS
COVER
GASKET
SCREEN
STRAINER BODY
DRAIN PLUG (ON REAR OF STRAINER)
THERMOMETER (ON FRONT OF STRAINER)
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.