
Installation
1-9
The temperature at the discharged cooling water should not exceed 130°F (54°C). If the water supply
pressure is low, it may be necessary to connect the different sections of cooling coils in parallel. This
should be done if the cooling water discharge temperature exceeds 130°F (54°C). The cooling water
discharge should, if possible, be connected to an open drain so that cooling water flow can readily be
checked.
b.
The quick-cool coil at the boiler plate MUST be connected to an open drain and the feed line
controlled by a separate water 3-way valve (open, closed, and vent to atmosphere). The drain
must be below the boiler level so that it is drained completely when the quick-cool coil water
supply is shut off and the pump is operating. See Figure 1-3.
1-6-4
Electrical Connections (See Figure 1-4a, b, c, d, or e Diffusion Pump Wiring Diagram)
WARNING
High voltages (up to 480V) can kill. Always break the primary circuit to
the pump before starting to work on the heater and/or its wiring.
a.
The pump heater has been designed to operate at a certain voltage. Check the heater for
correct supply voltage and, in the case of multiphase connections, for load balance by
measuring the resistance of each branch.
Heater circuit resistance (all 3-phase,
200V – 3.3 ohms
measured line-to-line)
240V – 4.8 ohms
460V – 17.6 ohms
415V – 14.4 ohms
480V – 19.2 ohms
b.
Make connections to the terminals in the junction box (at the foreline). The use of flexible
conduit is recommended to facilitate removal of the pump for service. The pump should not
be operated at more than 5% over the rated voltage. Make connections in accordance with
the wiring diagram provided with each pump.
1-6-5
Thermal Switches
The thermal switches have been pre-set at the factory and should not require adjustment. The lower
thermal switch is set at 550°F; the lower switch is set at 220°F. Should any thermal switch be thrown
out of adjustment, it can be adjusted as follows.
1.
Boiler thermal switch
The boiler thermal switch is mounted on a brass block at the center of the boiler.
The thermal switch should be adjusted, with the pump operating, as follows:
a)
After several hours operation, disconnect the lead wires and place an
ohmmeter across the terminals of the thermal switch.