Operating instructions

Chilled Water Flow Switch
A water flow switch must be mounted in the leaving chilled water line to prove that there is adequate
water flow to the evaporator before the unit can start. It also serves to shut down the unit in the
event that water flow is interrupted in order to guard against evaporator freeze-up.
A flow switch is available from McQuay under ordering number 017503300. It is a paddle-type
switch and adaptable to any pipe size from 1" (25mm) to 8" (203mm) nominal.
Table 14, Flow Switch Settings
inch 1 1/4 1 1/2 2 2 1/2 3 4 5 6 8 Pipe Size
(NOTE !)
mm 32 (2) 38 (2) 51 63 (3) 76 102 (4) 127 (4) 153 (4) 204 (5)
gpm 5.8 7.5 13.7 18.0 27.5 65.0 125.0 190.0 205.0
Flow
Lpm 1.3 1.7 3.1 4.1 6.2 14.8 28.4 43.2 46.6
gpm 3.7 5.0 9.5 12.5 19.0 50.0 101.0 158.0 170.0
Min.
Adjst.
No
Flow
Lpm 0.8 1.1 2.2 2.8 4.3 11.4 22.9 35.9 38.6
gpm 13.3 19.2 29.0 34.5 53.0 128.0 245.0 375.0 415.0
Flow
Lpm 3.0 4.4 6.6 7.8 12.0 29.1 55.6 85.2 94.3
gpm 12.5 18.0 27.0 32.0 50.0 122.0 235.0 360.0 400.0
Max.
Adjst.
No
Flow
Lpm 2.8 4.1 6.1 7.3 11.4 27.7 53.4 81.8 90.8
NOTES:
1. A segmented 3-inch paddle (1, 2, and 3 inches) is furnished mounted, plus a 6-inch paddle loose.
2. Flow rates for a 2-inch paddle trimmed to fit the pipe.
3. Flow rates for a 3-inch paddle trimmed to fit the pipe.
4. Flow rates for a 3-inch paddle.
5. Flow rates for a 6-inch paddle.
24 ACZ / AGZ-BM IMM ACZ/AGZ-4