AC-SVX003A-EN
59
NOTICE
Evaporator Damage!
Failure to follow these instructions could result in
damage to the evaporator.
If insufficient concentration or no freeze inhibitor is
used, the evaporator water flow must be controlled by
the unit controller AND heaters must be used to avoid
catastrophic damage to the evaporator due to
freezing. It is the responsibility of the installing
contractor and/or the customer to ensure that a pump
will start when called upon by the chiller controls.
Even with water pump control, a power loss of as little
as 15 minutes under freezing conditions can damage
the evaporator. Only the proper addition of freeze
inhibitor or complete drainage of the water circuit can
ensure no evaporator damage in the event of a power
failure.
Low Evaporator Refrigerant
Cutout, Glycol Requirements
The table below shows the low evaporator temperature
cutout for different glycol levels. Additional glycol beyond
the recommendations will adversely effect unit
performance. The unit efficiency will be reduced and the
saturated evaporator temperature will be reduced. For
some operating conditions this effect can be significant.
additional glycol is used, then use the actual percent glycol
to establish the low refrigerant cutout setpoint.
Note: Tables below are not substitutes for full unit
simulation for proper prediction of unit performance
with specific operating conditions. For information
on specific conditions, contact Trane product
support.
Table 21. Low evaporator refrigerant temperature cutout (LERTC) and low water temperature cutout (LWTC) — 150 to
330 ton units
Ethylene Glycol Propylene Glycol
Glycol
Percentage (%)
Solution
Freeze Point (°
F)
Minimum
Recommended
LERTC (°F)
Minimum
Recommended
LWTC (°F)
Glycol
Percentage (%)
Solution
Freeze Point (°
F)
Minimum
Recommended
LERTC (°F)
Minimum
Recommended
LWTC (°F)
0 32 28.6 35 0 32 28.6 35
2 31 27.6 34 2 31 27.6 34
4 29.7 26.3 32.7 4 29.9 26.5 32.9
5 29 25.6 32 5 29.3 25.9 32.3
6 28.3 24.9 31.3 6 28.7 25.3 31.7
8 26.9 23.5 29.9 8 27.6 24.2 30.6
10 25.5 22.1 28.5 10 26.4 23 29.4
12 23.9 20.5 26.9 12 25.1 21.7 28.1
14 22.3 18.9 25.3 14 23.8 20.4 26.8
15 21.5 18.1 24.5 15 23.1 19.7 26.1
16 20.6 17.2 23.6 16 22.4 19 25.4
18 18.7 15.3 21.7 18 20.9 17.5 23.9
20 16.8 13.4 19.8 20 19.3 15.9 22.3
22 14.7 11.3 17.7 22 17.6 14.2 20.6
24 12.5 9.1 15.5 24 15.7 12.3 18.7
25 11.4 8 14.4 25 14.8 11.4 17.8
26 10.2 6.8 13.2 26 13.8 10.4 16.8
28 7.7 4.3 10.7 28 11.6 8.2 14.6
30 5.1 1.7 8.1 30 9.3 5.9 12.3
32 2.3 -1.1 5.3 32 6.8 3.4 9.8
34 -0.7 -4.1 5 34 4.1 0.7 7.1
35 -2.3 -5 5 35 2.7 -0.7 5.7
36 -3.9 -5 5 36 1.3 -2.1 5
38 -7.3 -5 5 38 -1.8 -5 5
40 -10.8 -5 5 40 -5.2 -5 5
42 -14.6 -5 5 42 -8.8 -5 5
Installation Mechanical
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