Mammoth V-Cube User Manual

Page 35

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Serial Number: _____________________________________

Table C2: Start-up Checklist

Checklist Item

Yes

N/A

1

Before proceeding, complete the Pre Start-up Checklist.

2

Close all access panels or doors.

3

Turn the main disconnect to the ‘On’ position.

4

The unit can be started by using the keypad and selecting the mode of operation from the Keypad
Operation Guide and the Sequence of Operation. Run through the complete sequence of operation
of the unit, adjusting setpoints and documenting as required. Once completed, return the unit to the
correct mode of operation and adjust the time clock if required.

5

Are dampers operating properly?

6

Are fans rotating in the correct direction?

7

Adjust the supply air fan motor VFD to the correct supply air.

8

For occupied recirculation mode, adjust outside air and exhaust air damper positioner to achieve
the required air volumes.

9

Check amperage draw to each motor on each phase against motor nameplate FLA. If significantly
different, check ductwork static and/or take corrective action.

10

Recheck the voltage at the disconnect switch against the nameplate and against phase-to-phase
readings on three-phase with all blowers operating. If the voltage is not within 10% of rated or 2%
of phase-to-phase, have the condition corrected before continuing start-up.

11

Feel the compressor crankcases. They should be warm if the disconnect has been on for at least
24 hours. This will assure that no refrigerant liquid is present in the crankcase which could cause
compressor damage or failure to occur on start-up.

12

Before activating the compressor on WSHP units, are water shut-off valves open and is water circu-
lating through the water-to-refrigerant heat exchanger? Check the incoming line water pressure to
ensure it is within design and acceptable limits.

13

Enable cooling and check if the sound of the compressor is normal or if there is excessive vibration.

14

Check all field and factory refrigerant and water piping connections for leaks and correct.

15

On units with WSHP, after a few minutes of operation:
a. Check the supply discharge temperature status on the keypad for cooling air delivery. Mea-

sure the temperature difference between entering and leaving water. In cooling mode, the
temperature difference should be approximately 1.5 times greater than the heating mode
temperature difference. For example, if the cooling temperature difference is 15ºF [8.3ºC], the
heating temperature difference should be approximately 7ºF to 10ºF [3.9ºC to 5.6ºC]. Adjust
the combination shut-off/balancing valve in the return line to a water flow rate which will
result in the 7ºF to 10ºF [3.9ºC to 5.6ºC] difference. Alternatively, if a flow measuring valve or
pressure gauge connections are included, take the flow reading or pressure drop compared to
the submittal information and adjust the shut-off/balancing valve in the return line to the cor-
rect flow/pressure drop reading.

b. Measure the temperature difference between entering and leaving air and entering and leav-

ing water. With entering water of 60ºF to 80ºF [15.6ºC to 26.7ºC], leaving temperature should
rise through the unit (should not exceed 35ºF [19.4ºC]). If the air temperature exceeds 35ºF
[19.4ºC], then the water flow rate is inadequate or the airflow rate may be low and a second
check may be required after airflow balancing.

16

On units with integrated air cooled condensers, check condenser fans are rotating in the correct
direction. Measure the temperature difference between entering and leaving air.

17

On units with electric heating coils, check supply air proving interlock switch setting to ensure mini-
mum supply airflow prior to operation.

18

Enable heating options; see Start-up and check instructions in

Appendix E

for electric coil and complete.

19

For electric heating coil option, check the amp draw on each stage, the operation of the sequence
or SCR controller and the coil for any hot spots.

20

Check the operation of the control options provided on the unit.

21

Check the setpoints on the DDC Points Reference, adjust and record changes as required.

22

Has air balancing been completed for both occupied and unoccupied operation?

23

When unit has achieved steady state, take measurements and complete readings section of start-up
report!

VCES-V-CUBE-IOM-1A

35

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