Specifications

48
Table 35 — Temperature Limits for Standard Units
LEGEND
*Temperature limit for high condensing/heat reclaim option units are
140 F (60 C).
†For sustained operation, EWT should not exceed 85 F (29.4 C).
Pulldown can be accomplished from 95 F (35 C).
**Unit requires brine modification for operation below this
temperature.
VOLTAGE
Main Power Supply — Minimum and maximum acceptable
supply voltages are listed in the Installation Instructions.
Unbalanced 3-Phase Supply Voltage — Never operate a motor
where a phase imbalance between phases is greater than 2%.
To determine percent voltage imbalance:
The maximum voltage deviation is the largest difference
between a voltage measurement across 2 legs and the average
across all 3 legs.
Example: Supply voltage is 240-3-60.
AB = 243v
BC = 236v
AC = 238v
1. Determine average voltage:
2. Determine maximum deviation from average voltage:
(AB) 243 – 239 = 4 v
(BC) 239 – 236 = 3 v
(AC) 239 – 238 = 1 v
Maximum deviation is 4 v.
3. Determine percent voltage imbalance:
= 1.7%
This voltage imbalance is satisfactory as it is below the
maximum allowable of 2%.
MINIMUM FLUID LOOP VOLUME — To obtain proper
temperature control, loop fluid volume must be at least 3 gal-
lons per ton (3.25 L per kW) of chiller nominal capacity for air
conditioning and at least 6 gallons per ton (6.5 L per kW) for
process applications. Refer to application information in Prod-
uct Data literature for details.
FLOW RATE REQUIREMENTS — Standard chillers should
be applied with nominal flow rates within those listed in the
Evaporator and Condenser Flow Rates table. Higher or lower
flow rates are permissible to obtain lower or higher tempera-
ture rises. Minimum flow rates must be exceeded to assure
turbulent flow and proper heat transfer in the cooler. See
Table 36. See Fig. 27-43 for cooler pressure drop curves.
Consult application data section in the Product Data
literature and job design requirements to determine flow rate
requirements for a particular installation.
TEMPERATURE F C
Maximum Condenser EWT 110 43.3
Minimum Condenser EWT 65 18.3
Maximum Condenser LWT* 118 47.8
Maximum Cooler EWT† 70 21.1
Maximum Cooler LWT 60 15.6
Minimum Cooler LWT** 40 4.4
EWT — Entering Fluid (Water) Temperature
LWT — Leaving Fluid (Water) Temperature
% Voltage Imbalance = 100 x
max voltage deviation from
avg voltage
average voltage
Average voltage =
243+236+238
3
=
717
3
= 239
% Voltage Imbalance = 100 x
4
239
IMPORTANT: If the supply voltage phase imbal-
ance is more than 2%, contact the local electric
utility company immediately. Do not operate unit
until imbalance condition is corrected.
CAUTION
Operation below minimum flow rate could generate alarms
and result in damage to the cooler.