Trane RTAA-100, Installation & Maintenance Manual

Page: 98 / 178

98 RTAA-SVX01A-EN
Controls Interface
Low Ambient Temperature Start
The Low Refrigerant Temperature Cutout (LRTC) and Low Pressure Cutout
(LPC) on a circuit is ignored, briefly, each time the circuit is started. The
“ignore time” is a function of the Saturated Condenser Refrigerant Temper-
ature at the time the compressor starts, as shown in Figure 36.
Table 17 Leaving Fluid Temperature Setpoints
The leaving chilled water temperature is not the same as the ice termination setpoint. The
ice termination setpoint is based on entering chilled water temperature. Therefore, the ice
termination setpoint, minus temperature drop across the evaporator while in the ice
making mode, equals the leaving chilled water temperature.
Leaving
Chilled Water
Temp - F Leaving
Water Temp
Cutout - F Low
Refrig Temp
Cutout - F
Recommended***
% Ethylene Glycol Solution
Freeze Point - F
40 35 22 0 32
39 34 20 3
38 33 18 6
37 32 17 8
36 31 15 10 25
35 30 14 12
34 29 12 14
33 28 11 15 21
32 27 9 17
31 26 7 19
30 25 6 20 16
29 24 4 21
28 23 2 23
27 22 0 25 10
26 21 -1 26
25 20 -3 28
24 19 -5 29
23 18 -6 30 4
22 17 -8 31
21 16 -10 33
20 15 -11 34
19 14 -13 35 -3
18 13 -15 36
17 12 -17 37
16 11 -18 38
15 10 -19 39
14 9 -21 40 -11
13 8 -23 41
12 7 -24 42
11 6 -26 43
10 5 -27 43
9 4 -29 44
8 3 -31 45 -21
7 2 -32 46
6 1 -34 47
5 0 -35 47
4 -1 -37 48
3 -2 -38 49
2 -3 -39 50 -32
1 -4 -39 50
0 -5 -39 50
***Recommended% Ethylene Glycol will give freeze protection consistent with other chiller
safety controls (solution freeze point is nominally 10'F above refrig temp cutout).