Temptek G-500 Series, Instruction Manual

Page: 47 / 64

Temperature Control Unit : VTO Series with G500 Series Instrument
Page: 47
TEMPTEK, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-6352 Fax: 317-881-1277
Email: service@Temptek.com
5.5 WATER PRESSURE SWITCH SERVICE
A. Water is used for pump seal cooling and for the optional cooling heat exchanger. It is
important to have an adequate water supply. Water pressure is used as an indication
adequate water supply to the unit. The unit is protected from low pressure operations by
a water pressure switch. This switch is mounted on the water supply manifold.
B. The switch will close and consent the control circuit when sufficient water supply pressure
is presented. The switch is factory set to 20 psi.
C. If insufficient water supply pressure is present, the switch will open and prevent
operations.
1. Shut down unit operations. Be certain proper lock-out procedures are followed.
Also, be certain system pressure is eliminated and the unit’s pressure gauges
read “0” pressure.
2. Drain unit by removing the pump casing drain plug.
3. A capillary runs from the cooling cylinder to the pressure switch. Remove the
capillary connection.
4. The brass elbow mounted on the pressure switch must be removed.
5. Remove the electrical connections to the pressure switch.
6. The pressure switch is mounted onto the electrical cabinet with two 1/2” nuts in
series. Remove the nuts to remove the pressure switch. A new pressure switch
from the factory should be installed by continuing with step 7.
7. Thread one 1/2” nut onto the pressure switch and then place the pressure switch
through the panel in the original mounting hole. Thread the second 1/2” nut from
the bottom of the pressure switch. Tighten to lock the pressure switch in place.
8. Install the brass elbow fitting. Teflon tape and leak preventative paste should be
used to prevent water leakage. Install the capillary tube and resume operations.