Johnson Controls YORK PYT 0330 Instruction Manual page 27

Draining the system for all PYT model drives
The drive water-to-water heat exchanger is the primary location for draining the coolant loop. See
the wiring diagrams in External piping components for all PYT model drives
thread (GHT) locations on each drive model. Collect and dispose of all fluids drained from the drive
in accordance with local policy and regulations.
1. De-energize and lock out the drive using all applicable policies and appropriate drive service
literature.
2. Remove the coolant reservoir cap.
3. Attach the drain hose to the GHT faucet valve on the bottom of the shell and tube heat
exchanger.
4. Place the other end of the hose in a suitable container for disposal of the trapped liquid.
5. Open the heat exchanger valve to allow coolant to drain. After the coolant stops flowing,
close the valve.
Note: Monitor the drain process because the 5 gal bucket may need to be emptied
before the draining is complete.
Result
The system is now drained.
Table 7: PYT drive coolant and inhibitor quantities
Drive model
PYT0330
PYT0420
PYT0780
PYT1020
PYT1050
PYT1280
PYT1620
Chillers with YORK Liquid-Cooled Variable Speed Drives and Starters
Coolant capacity (gal)
3
3
4
4
6
6
10
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for the garden hose
Recommended inhibitor
amount (gal)
3
3
3
4
4
6
10
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