Pre-Start-up
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I 1.
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Open all electrical disconnects and check electrical connections are tight.
Verify water piping flow directions are correct and properly connected at the evaporator and
condenser.
Using a phase tester, verify electrical phasing is A-B-C clockwise (A=L I, B=L2.C=L3).
Verify unit power supply is within
1 0 %
of nameplate rating.
Verify power supply wiring is the correct size and has a minimum temperature insulation rating of
75°C.
Verify all mechanical and electrical inspections have been completed according to local code.
Make certain all auxilliary control equipment is operative and an adequate cooling load is
available.
Check all compressor valve connections for tightness.
Open compressor suction valve until backseated. (This is an optional valve)
Open discharge shutoff valve until backseated
Vent air from the evaporator and condenser water system piping.
Open all water tlow valves and start chilled water pump.
Check all piping for leaks.
Flush the evaporator and condenser system piping.
Sequence of Operation
The following sequence of operation is typical for McQuay models PFS 150B through PFS2 15B
rotary screw water chillers. The sequence may vary depending on the software revision or various
options that may be installed on the chiller.
Initial Conditions
Before energizing the control box do the following:
1.
Verify the two control circuits are powered through the primary fuses FU1 and FU2 and the
secondary fuse FU3.
2.
Verify the power developed through the transformer CPT in the starter is 120 Vac on the
secondary.
3. Verify front panel switch is in the off position.
When applying power to the control for the first time do the following:
1.
Open the left door and the top door to each control box.
2. Observe when power is applied the display lights up and when the Unit Status screen appears the
EXV board lights rapidly sequence closed.
3. Listen for the stepper motors closing with a ratcheting sound.
IM 663 25
