Carrier AquaEdge 19DV series - FINE TUNING VPF SURGE PREVENTION

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COOLER-CONDENSER — High side float chamber, relief
devices, refrigerant charging valve, temperature sensor loca-
tions, pressure transducer locations, Schrader fittings, water-
boxes and tubes, and vents and drains.
MOTOR COMPRESSOR ASSEMBLY — Guide vane actu-
ator, transmission, motor cooling system, temperature and
pressure sensors, sight glasses, motor temperature sensors, and
compressor serviceability.
COMPRESSOR LUBRICATION SYSTEM — Valves, dry-
ers and filters, liquid level switch and inhibitor reclaim system.
ECONOMIZER — Float valve, drain valve, Schrader fitting,
damper valve.
CONTROL SYSTEM — CCN and LOCAL start, reset,
menu, softkey functions, HMI operation, occupancy schedule,
set points, safety controls, and auxiliary and optional controls.
PURGE — Check for potential leaks by monitoring purge
hours in RUNTIME. Note changes over time.
AUXILIARY EQUIPMENT — Starters and disconnects,
separate electrical sources, pumps, and cooling tower.
DESCRIBE CHILLER CYCLES — Refrigerant, motor
cooling, lubrication, and liquid reclaim.
REVIEW MAINTENANCE — Scheduled, routine, and ex-
tended shutdowns, importance of a log sheet, importance of
water treatment and tube cleaning, and importance of maintain-
ing a leak-free chiller.
SAFETY DEVICES AND PROCEDURES — Electrical dis-
connects, relief device inspection, and handling refrigerant.
CHECK OPERATOR KNOWLEDGE — Start, stop, and
shutdown procedures, safety and operating controls, refrigerant
charging, and job safety.
REVIEW THE START-UP, OPERATION, AND MAINTE-
NANCE MANUAL.
FINE TUNING VPF (VARIABLE PRIMARY FLOW)
SURGE PREVENTION — Figures 32-35 show how the pa-
rameters defined below will affect the configured surge line.
The menu can be found under MAIN MENU CONFIGU-
RATION MENU SURGE CORRECTION CONFIG.
NOTE: Before tuning surge prevention, check for VFD
(variable frequency drive) speed limitation or capacity
overrides. If the source of low capacity is found in one of
these places, do not proceed with an attempt to tune the
Surge Prevention configurations.
If capacity is not reached
and
1. ACTUAL GUIDE VANE POSITION < GUIDE VANE
TRAVEL RANGE
and
2. SURGE PREVENTION ACTIVE = YES (can be identi-
fied in MAIN MENU MAINTENANCE MENU 
SURGE CORRECTION)
and
3. PERCENT LINE CURRENT < 100%
then the surge line is probably too conservative.
Note the following parameters from HMI when maximum
ACTUAL LINE CURRENT is achieved:
• EVAPORATOR REFRIGERANT TEMP
• EVAPORATOR PRESSURE
• CONDENSER REFRIG TEMP
• CONDENSER PRESSURE
• ACTUAL GUIDE VANE POSITION
• ACTUAL LINE CURRENT
The ACTIVE DELTA TSAT and the CALC REF DELTA
TSAT can be monitored on the MAINTENANCE MENU 
SURGE CORRECTION screen. When ACTUAL DELTA
TSAT exceeds CALC REF DELTA TSAT + ENVELOPE
LINE OFFSET surge prevention will occur.
If ACTUAL GUIDE VANE POSITION is less than 30%,
then increase SURGE DELTA TSMIN in steps of 2ºF (1.2ºC)
until one of the three conditions listed above no longer applies.
Do not change SURGE DELTA TSMAX.
If ACTUAL GUIDE VANE POSITION is greater than
60%, then increase SURGE DELTA TSMAX in steps of 2ºF
(1.2ºC) until cooling capacity is reached or one of conditions
listed above no longer applies. Do not change SURGE/HGBP
DELTA TSMIN.
If ACTUAL GUIDE VANE POSITION is more than 30%
AND less than 60%, then:
1. Increase SURGE DELTA TSMIN in steps of 2ºF (1.2ºC).
2. Increase SURGE DELTA TSMAX in steps of 2ºF (1.2ºC).
3. Repeat Steps 1 and 2 until one of the conditions listed
above no longer applies.
NOTE: DELTA TSMIN should seldom need to be increased
more than 10 degrees above the selection program value.
Likewise, DELTA TSMAX rarely requires more than a 2ºF
(1.2ºC) increase.
If surge is encountered then the controls surge prevention
algorithm surge line is probably too optimistic or high. Note
following parameters from HMI at surge:
• EVAPORATOR REFRIGERANT TEMP
• EVAPORATOR PRESSURE
• CONDENSER REFRIG TEMP
• CONDENSER PRESSURE
• ACTUAL GUIDE VANE POSITION
• AVERAGE LINE CURRENT
Fig. 32 — Effect of SURGE DELTA TSMIN on Surge
Prevention
0
5
10
15
20
25
30
35
40
0 102030405060708090100110
Tsmin=30
Tsmin=40
Tsmin=50
GV_POS
Delta Tsat