Rockwell Automation 7000L PowerFlex 7000 Medium Voltage AC Drive C Frame - Marine - Manual (Page 250)

4-74 Component Definition and Maintenance
7000L-UM302B-EN-P – June 2013 7000 ―C‖ Frame - Marine
Repair Instructions - Element Testing
Place element in water at a temperature 8°C to 1°C (15°F to 2°F)
above its nominal setting and stir water vigorously with the element
for five minutes. The temperature stamped on the side of the
element is not the nominal temperature; it is the temperature at which
the element is set to open. The stamped temperature is usually 6°C to
8°C (10°F to 15°F) higher than the nominal. After stirring
vigorously, immediately place the element in the housing. If the
element is fully stroked, the seating and over-travel spring can be felt
as it is pushed down. To determine if the element will close at a
specific temperature, place the element in a bath of water
approximately 3°C (5°F) below the start to open temperature. This is
the number stamped on the element. Due to the effect of hysteresis,
the element will close 3°C (5°F) below the start to open temperature.
Element Replacing
(Refer to Figure 4.58)
1. Remove four cap screws, lock-washers and separate upper
housing and lower housing.
2. Remove element assembly and seal.
3. Remove housing gasket. Clean housing sections and remove any
scale or foreign material from seal faces.
4. Lubricate the new element seal and slide it in place over top of
the element assembly into position shown in section view.
5. Place new housing gasket in recess of upper housing.
6. Insert element into upper housing to position shown in section
view.
7. Place lower housing over exposed section of element against
face of upper housing.
8. Secure housings with cap screws and lock-washers.
Seal Type
with ―O‖ Ring
with Lip Seal
Upper housing
Lock-washer
Sleeve
Gasket
Cap-screw
Element assembly
Lower housing
―O‖ Ring or Lip Seal
Figure 4.58 – Element Assembly Cross-Section
Pump Maintenance and
Replacement (cont.)