RESISTANCE
SPD50H
SPD100H
1Ø Start
1Ø Main
3Ø Bal.
1Ø Start 1Ø Main
3Ø Bal.
115V 6.53
1.90
-
-
-
-
230V 6.53
3.80
5.06
3.06
9.7
460V -
-
-
-
9.7
9.
For three phase pumps, remove the power cord assembly by cutting the butt connection and wire nuts and
remove the power cord from the pump.
10.
Twist the three leads of one end of the power cord together. Then at the other end, with an ohmmeter, check
any two leads. Also check the third lead with either of the first two. If a zero reading is indicated for any wire,
the wire is broken and a new power cord assembly must be ordered.
11.
If the winding is grounded, remove the pipe plug in the top of the pump and drain the oil into a cleaner
container. A milky appearance to the oil will indicate that water has entered through worn or damaged seals or
O-rings. If this is the case, the mechanical seals and all O-rings will have to be replaced.
Seal Housing
The pump is equipped with two mechanical seals mounted in tandem. The lower weal and the upper seal consist of
a ceramic stationary seat and a carbon rotating ring.
As noted, if water is detected in the motor housing, inspect the power cord connection, pipe plug connections, O-
rings, the motor housing itself, and the two mechanical seals.
There are two quarts of oil in the motor housing. This is a paraffin SE-40 process oil. The same oil is used in the
seal housing between the two mechanical seals. To check the seals, remove the lower housing pipe plug and pour
the oil out into a clean, preferably glass, container. Look for the milky color as noted previously.
If the oil is clear, the lower seal is still good. If this seal is damaged, water will seep in and continue to stain the oil,
changing it from clear, to slightly discolored, to cloudy, and finally to a milky white.
Except for very rare instances, the motor will continue to be protected by the upper mechanical seal.
Lower Seal
If water is found in the seal chamber, the lower seal must be replaced. Separate the volute by removing the three
cap screws holding the base to the upper volute.
Insert a large screwdriver in the slotted pump shaft and strike the impeller sharply with a plastic or rubber headed
hammer. The impeller should spin free. The impeller holds the rotation carbon ring of the lower mechanical seal
against the stationary ceramic seat by compressing a stainless steel spring.
When the impeller is removed, the spring will relax, allowing the carbon ring to be removed. There is a rubber
sleeve (bellows) inside the spring which grips the pump shaft. This often restricts the spring and must be pried or
pulled loose.
With the carbon ring, spring, and rubber sleeve removed, wedge the ceramic seat out of the housing. Be sure not to
scratch or mar the pump shaft.
