ClimaCool UGW Manual - Manual (Page 26)

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24
Startup
18 . Verify proper communications from each module back
to the master controller using the “STATUS” menu, then
indexing down to the desired compressor data screen .
• If the compressor data parameters all read “0,”
then communications are not yet established, and
communications cable troubleshooting is required .
• When all compressor data parameters read actual
values which agree with the refrigerant gauge set and
refrigerant line temperatures, then it is safe to assume
that communications are established .
19 . Set up the master controller parameters according to
the specific job submittal sheets.
• All parameters can be found in the FN 2 menu (setup),
FN 6 menu (module factory settings), FN 7 menu
(service), FN 8 menu (master factory settings).
•It is imperative to access EVERY MENU and EVERY
PARAMETER to ensure all settings are appropriate .
20 . Set up the Building Automation System (BAS) interface
parameters (as required) using the FN 0 menu (network
number selection, IP addressing), FN 4 menu (device
instances) .
Adjusting Unit Charge and Expansion Valves
Using Superheat and Subcooling Method
Due to varying installation conditions/applications and
to optimize performance, proper refrigerant charge and
expansion valve (TXV) adjustment must be confirmed.
After checking compressor rotation, choose a circuit to be
tested first. Connect test equipment to monitor the suction
line and liquid line temperatures simultaneously . Place a
manifold gauge set on the suction line and liquid line then
start the compressor . As long as the suction pressure is high
enough to prevent the low pressure switch from tripping,
run the compressor for five minutes.
Verify proper subcooling . This is accomplished by
subtracting the liquid line temperature from the saturated
condensing temperature . The saturated condensing
temperature is found by converting the liquid line pressure
reading on the manifold gauge to the related temperature .
The normal subcooling temperature range at the condenser
is 5-15°F BUT for total accuracy, please follow the charge
recommendations found in the selection program . If
subcooling is too low, then refrigerant must be added to the
system. Add charge and wait five minutes before checking
results . If subcooling is too high, then refrigerant must be
removed from the system .
Verify proper superheat by subtracting the saturated
evaporative temperature from the suction line temperature .
The saturated evaporative temperature is found by
converting the suction pressure reading on the manifold
gauge to the related temperature . The proper superheat
temperature range is 4-15°F at normal operating conditions
(typically 44 o F leaving chilled water temperature) . If
superheat is low, this may indicate that the expansion valve is
overfeeding . To adjust the expansion valves, turn the adjustment
stem clockwise. This will cause the superheat to rise. Wait five
minutes before checking the results of this adjustment . Repeat
until the desired superheat is achieved .