
18
SECTION D: PREVENTATIVE MAINTENANCE
As the motor and seal chamber are oil-fi lled, no lubrication or
other maintenance is required, and generally Deming Pumps
will give very reliable service and can be expected to operate
for years of normal sewage pumping without failing. However,
as with any mechanical piece of equipment a preventive
maintenance program is recommended and suggested to
include the following checks:
1) Test moisture detector control “Test Switch” for
continuity of circuit. Water in the seal chamber will
energize a seal leak warning light at the control
panel. This is a warning light only and does not
stop the motor. It indicates the seal has leaked
and must be repaired. This should be done within 2
or 3 weeks to prevent further damage. See section
C-2.2.
2) Inspect impeller and body for excessive build-up or
clogging and repair as required per section E-2.
3) Inspect outer shaft seal and replace as required per
section E-3.
4) Check motor for ground leakage and proper amp
draw.
SECTION E: SERVICE AND REPAIR
NOTE: All item numbers in ( ) refer to Figures 10, 11, 12 & 13.
WARNING ! - Electrical power to the pump
motors must be disconnected and locked
out to prevent any dangerous electrical
hazards or personnel danger before any
service work is done to the pump.
CAUTION ! - Operating pump
builds up heat and pressure;
allow time for pump to cool
to room temperature before
handling or servicing.
E-1) Lubrication
E-1.1) Checking Oil
1. Place pump on it’s side, and drain oil into a clean, dry
container.
2. Check oil for contamination using an oil tester with a range
to 30 Kilovolts breakdown.
3. If oil is found to be clean and uncontaminated (measure
above 15 KV. breakdown), refi ll the seal chamber as per
section E-1.2.
4. If oil is found to be dirty or contaminated (or measures below
15 KV. breakdown), the pump must be carefully inspected
for leaks at the shaft seal (4), before refi lling with oil. To
locate the leak, perform a pressure test as per section E-1.3.
After leak is repaired, refi ll with new oil as per section E-1.2.
E-1.2) Replacing Oil:
Seal Chamber - Drain all oil from seal chamber and dispose
of properly. Refi ll with (see parts list for amount) (Oil amount
for seal chamber for 18 frame pumps = 47oz. +/- 1 oz.)
new cooling oil as per Table 1. An air space must remain to
compensate for oil expansion (See Fig. 10 and Fig. 11). Set
unit on side and fi ll.
IMPORTANT! - Do not overfill oil.
Overfilling of seal chamber with oil can
create excessive and dangerous hydraulic
pressure which can destroy the pump
and create a hazard. Overfilling oil voids
warranty.
E-1.3) Pressure Test:
Seal Chamber - Before checking the pump for leaks around
the shaft seal, the oil level should be full. Remove pipe plug.
Apply pipe sealant to pressure gauge assembly and tighten
into pipe plug hole. Pressurize motor housing to 10 P.S.I. Use
a soap solution around the sealed area and inspect joints for
“air bubbles”. If, after fi ve minutes, the pressure is still holding
constant, and no “bubbles” are observed, slowly bleed the
pressure and remove the gauge assembly. Replace the pipe
plug using a sealant. If the pressure does not hold, then the
leak must be located.
CAUTION! - Pressure builds up extremely
fast, increase pressure by “tapping” air
nozzle. Too much pressure will damage
seal. Do Not exceed 10 P.S.I. in seal
chamber.
TABLE 1 - COOLING OIL - Dielectric
SUPPLIER GRADE
BP Enerpar SE100
Conoco Pale Paraffi n 22
Mobil D.T.E. Oil Light
G & G Oil Circulating 22
Imperial Oil Voltesso-35
Shell Canada Transformer-10
Texaco Diala-Oil-AX
Woco Premium 100
E-2) Impeller and Volute Service:
E-2.1) Disassembly and Inspection:
To clean out the volute (11), or clean out or replace impeller
(6), disconnect power, remove cap screws (2) then vertically
lift motor assembly from the pump body (11). Clean out the
volute, if necessary, clean and examine impeller (6) for pitting
or wear, replace if required. To remove Impeller (6), remove
cap screw (8) and washer (8A). The impeller is keyed onto the
shaft with a square key (7) and to remove, pull impeller straight
off the shaft using a wheel puller if required. Inspect o-ring (9)
and replace if cut or damaged. Before reinstallation, check the
motor shaft and impeller bore for damage.
E-2.2) Reassembly:
To install impeller (6), apply a thin fi lm of oil to motor shaft
and slide impeller straight onto shaft, keeping keyways
lined up. Drive key (7) into keyway. Thread cap screw (8)
and washer (8A) into shaft and torque to 45 ft. lbs. Rotate
impeller to check for binding. Place o-ring (9) on seal plate
pilot diameter lining up holes and install impeller and motor
assembly onto volute (11). Loctite cap screws (2), insert into
volute and motor assembly and torque to 35 ft. lbs. Check for
free rotation of motor and impeller.