The two-way motorized water shut-off valve is an ac-
cessory item and consists of a 24 VAC NEMA 1 or 2 on/
off actuator with a temperature rating of −22°F to 122°F
[−30°C to 50°C], nickel plated forged brass valve and
replaceable valve cartridge assembly which must be ex-
ternally field mounted. For outdoor applications a NEMA
4x rated actuator must be installed. The hydronic valves
are intended for use in a normal indoor/outdoor environ-
ment for hot or cold water or glycol solutions to 60%
concentration with a medium temperature rating of 0°F to
212°F [−18°C to 100°C]. The actuator must be field wired
to the standard field wiring terminals #435, 436 and 437
depending on valve size. The valve and actuator are pre-
assembled for 0% flow to the coil when the unit does not
require heating or cooling.
See Table I3 for two-way valve sizing, performance data
and dimensions; installation and technical data is included
with accessory parts. See the wiring schematic for con-
nection information.
Freeze Protection
A water flow switch and a temperature sensor as an op-
tion and mounted on the water return or leaving side of
the condenser are used to monitor the presence or ab-
sence of flow and the water temperature which will shut
down the compressor and unit for freeze protection. The
flow switch also features an adjustment which allows the
user to change the switch from normally open (NO) to nor-
mally closed (NC).
The temperature sensor is factory mounted and wired in-
ternally. The flow switch must be externally field mounted
in the leaving or return water line and field wired to the
standard field wiring terminal strip as per wiring sche-
matic. See performance, dimensions and installation data
at the end of this appendix.
Table I2: Three-way Head Pressure Control Valve Sizing and Performance Data
Circuit
Number
Tons
Minimum
US GPM
2
Condenser Pressure
Drop (PSI)
1
Condenser
Maximum
Pressure (PSI)
Three-way Head Pressure Control Valve
Cv1
Maximum Pressure
(PSI)
Size FPT
Single
circuit
2
6
4.4
400
3.0
600
½
3
9
4.5
400
3.0
600
½
4
12
3.2
400
4.7
600
¾
5
15
5.7
400
7.4
600
¾
6
18
7.6
400
7.4
600
1
8
22
3.5
400
7.4
600
1
10
30
5.7
400
10.0
400
1¼
12
36
8.7
100
19.0
400
1¼
14
42
7.3
400
19.0
400
1¼
16
44
3.8
400
19.0
400
1¼
Dual
circuit
6
18
4.7
400
7.4
600
1
8
22
3.5
400
7.4
600
1
10
30
5.7
400
10.0
600
1¼
12
36
8.7
400
19.0
400
1¼
14
35
4.2
350
19.0
400
1¼
16
40
5.4
350
19.0
400
1¼
21
53
5.2
350
25.0
400
1¼
* Three-way head pressure control valve diverts flow into coax coil.
1 – Values are based on water.
2 – Please refer to Venmar Select™ Web Edition for minimum and maximum GPM values.
VCES-VHC-IOM-1F – VHC-36, -42 & -50
49
