Application Data - Carrier 30HR Product Data

Application data

Leveling unit
To assure proper oil return, be sure that unit is level,
particularly in its major lengthwise dimension, as com-
pressor oil return piping runs in that direction.
Determine prior to installation if any special treat-
ment is required to assure a level installation.
Cooler fluid temperature
1. Maximum leaving chilled fluid temperature (LCWT) is
70 F (21 C). Unit can start and pull down with up to
95 F (35 C) entering fluid temperature due to MOP (maxi-
mum operating pressure) feature of the expansion valve.
For sustained operation, it is recommended that enter-
ing fluid temperature not exceed 85 F (29 C).
2. Minimum LCWT is 40 F (4 C) for standard units. Spe-
cial order medium temperature brine units must be
ordered for operation with leaving fluid temperatures
in the range of 39 to 15 F (4 to −9 C). For ratings
below 40 F (4 C) LCWT, contact your local Carrier
representative.
Condenser fluid temperature
1. Maximum leaving condenser fluid temperature is
104 F (40 C) on all 30HR models (except 30HR160,
which has a maximum temperature of 120 F [49 C]).
2. Minimum entering condenser fluid temperature without
condenser flow regulation is 70 F (21 C).
MINIMUM COOLER AND CONDENSER FLUID
FLOW RATES AND MINIMUM LOOP VOLUME
MINIMUM FLOW
UNIT
Cooler
30HR,HS
Gpm L/s
070 95 5.99
080 95 5.99
090 95 5.99
100 135 8.52
110 135 8.52
120 135 8.52
140 156 9.84
160 156 9.84
LEGEND
ARI — Air Conditioning and Refrigeration Institute (U.S.A.)
N — Liters per kW
V — Gallons per ton
*Applicable to 30HR units only.
†Minimum system fluid volumes:
Gallons = V x ARI Capacity in Tons
Liters = N x ARI Capacity in kW
(Based on Normal Air Conditioning value)
APPLICATION
Normal Air Conditioning
Process Type Cooling
Low Ambient Operation
NOTE: Minimum condenser fluid flow based on 3 ft/sec (0.9 m/s) to
minimize condenser fouling. Flow rates below 3 ft/sec (0.9 m/s) may
require more frequent tube cleaning.
Cooler and fluid-cooled condenser
temperature rise
Ratings and performance data in this publication are for a
cooling temperature rise of 10° F (5.6° C). Units may be
operated at a different temperature rise, provided flow lim-
its are not exceeded and corrections to capacity, etc., are
MINIMUM
VOLUME†
Condenser*
Gpm L/s Gal. L
110 6.94 208 787.3
115 7.26 232 878.1
124 7.82 257 972.7
128 8.08 294 1112.8
138 8.71 315 1192.3
150 9.46 336 1271.8
150 9.46 405 1532.9
243 15.30 449 1699.5
V N
3 3.25
6 to 10 6.5 to 10.8
6 to 10 6.5 to 10.8
made. For minimum flow rates, see Minimum Cooler and
Condenser Fluid Flow Rates and Minimum Loop Volume
table on this page. High flow rate is limited by pressure drop
that can be tolerated. If another temperature rise is used,
apply LCWT correction as given in Selection Procedure sec-
tion on page 17.
Minimum cooler flow — This value (maximum cooler tem-
perature rise) for standard units is shown in Minimum Cooler
and Condenser Fluid Flow Rates and Minimum Loop Vol-
ume table. When gpm (L/s) required is lower (or rise is
higher), follow recommendations below:
a. Multiple smaller chillers may be applied in series, each
providing a portion of the design temperature rise.
b. Chilled fluid may be recirculated to raise flow rate. How-
ever, mixed temperature entering cooler must be main-
tained at a minimum of at least 5° F (2.8° C) above the
leaving chilled fluid temperature.
c. Special cooler baffling is required to allow minimum flow
rate to be reduced 12%.
NOTE: Recirculation flow is shown below.
RECIRCULATION FLOW
Maximum cooler flow (
[ 0.09 L/s kW or 2.7° C rise]) — The rise results
•
in practical maximum pressure drop through cooler.
Return fluid may bypass the cooler to keep pressure drop
through cooler within acceptable limits. This permits a higher
T with lower fluid flow through cooler and mixing after
the cooler.
Special cooler baffling is available by special order, to per-
mit a cooler flow rate increase of 10%.
NOTE: Bypass flow is shown below.
BYPASS FLOW
5 gpm/ton or 5° F rise
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