Mammoth 800 to 5500 CFM: Dedicated Outdoor Air System with Enthalpy Wheels (VHC) - Manual (Page 46)

MAMM-VHC-IOM-1A (JANUARY 2013) 46
Water Flow Switch
Flow Switch Dimensions
Flow Switch Installation
The flow switch must be externally field mounted in the
leaving or outlet water line. Before installation, the flow
switch vane must be trimmed for the size of piping being
used. A full size, trimmable stainless steel vane is provided
with a removable laminate template. This template is cali-
brated for brass or ductile iron reducing tee and forged
steel straight tee/brushing combination which allows for
field installation in pipeline from ½” to 2” diameter. See
Table K11 for approximate actuation and deactivation val-
ues.
1. Carefully unpack the flow switch and remove any
packing material from the lower housing. Trim the
vane at the appropriate mark for the size of piping
being used.
2. Apply thread tape or sealant to the ½” male NPT
mounting threads and install the flow switch in the sys-
tem piping with the arrow on the side pointing in the
direction of flow.
3. The flow switch must be field wired to the standard
field wiring (FW) terminal strip as per wiring schematic
for 24 VAC.
4. Avoid exceeding any of the maximum electrical ratings
which can lead to failure.
5. After installation, set the switch action to normally
open or normally closed. To change the switching
from normally open to normally closed, loosen, but
do not remove the two screws on the top cap. Slide
the reed switch assembly to expose the switch ac-
tion selected. Tighten screws when adjustment is
complete.
1
1
2
2
3
3
4
4
5
5
One screw attaches
actuator to valve
Four actuator mounting
positions
Two-way flow pattern
Three-way flow pattern
(mixing shown)
Top of valve stem indicates
direction of flow
(Flow A to AB shown)
Note: For diverting flow, flow
enters in AB and diverts
to A and B ports.
CCW
CCW
4 x 90°
A
A
AB
AB
B
A-AB = 100%
A-AB = 100%
B-AB = 0%
Figure K14: Valve and actuator assembly and installation
WARNING
Mechanical shock or vibration can cause permanent
damage to the switch. Avoid dropping the unit on hard
surfaces.
!
Figure K15: Valve and actuator assembly and installation
2¼” [57 mm]
1” [25 mm]
¼ (6) travel to
normally closed
position
(2) 22 AWG Leadwires
18 (460) long
1/8 NPT – switch shown
in normally open position
Lower body
7/8 hex
½ NPTM
Vane 2-7/16” [62 mm]
2-7/8” [73 mm]
Table K11: Flow Switch Performance Data Table
Cold Water Flow Rates –
Approximate Actuation/Deactuation
Pipe Trim NO NC
½” L
2.6/2.3 2.6/2.5
9.8/8.7 9.8/9.5
¾” J
3.1/2.7 3.1/2.8
11.7/10.2 11.7/10.6
1” H
4.8/4.5 4.8/4.4
18.2/17.0 18.2/16.7
1¼” E
6.2/5.6 6.1/5.6
23.5/21.2 23.1/21.2
1½” C
8.2/7.7 8.2/7.7
31.0/29.1 31.0/29.1
2” Full
9.5/9.1 9.5/9.0
36.0/34.4 36.0/34.1
GPM upper, LPM lower