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VAPORSTREAM INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Wiring:
CONTROL WIRING
The following wiring methods for external low voltage control wiring should
minimize electrical noise problems:
• Humidistat, room/duct transmitter, and temperature transmitter wiring must
be minimum 18-gauge (1 mm
2
) plenum rated, shielded (screened), twisted
pair wire with a bare drain wire for grounding.
• Airfl ow proving switch wiring must be minimum 18-gauge (1 mm
2
) stranded
wire run in conduit. The airfl ow proving switch can be wired using minimum
18-gauge (1 mm2) plenum rated, shielded (screened), twisted pair wire
with a bare drain wire for grounding.
• The shield (screen) wire should be connected to the shield (screen) ground
terminal/lug with a length less than 2" (51 mm). Do not ground the shield
(screen) wire on the humidistat or transmitter end.
• Water level control device, thermal trip, humidifi er cover interlock, fi ll valve,
and drain valve wiring must be minimum 18-gauge stranded wire run in a
separate conduit from power wires. DO NOT USE SHIELDED (SCREENED)
CABLE FOR WATER LEVEL CONTROL DEVICES.
• The tank temperature sensor can be run with 18-gauge (1 mm2) stranded
wire if the control cabinet is located within 10' (3 m) of the humidifi er. For
wire lengths of 10' to 50' (3 m to 15 m), use 18-gauge (1 mm2) plenum
rated,
shielded
(
screened
), twisted pair wire with a bare drain wire for
grounding.
GROUNDING REQUIREMENTS
The approved earth ground must be made with solid metal-to-metal connections
and must be a good con duc tor of radio frequency interference (RFI) to earth
(multistranded conductors).
Ground wire should be the same AWG (mm
2
) size as the power wiring or
sized per NEC requirements (in Europe, IEC 60364 requirements).
When the control cabinet is mounted remotely from the humidifi er, a ground
wire is necessary from the machine ground lug on the humidifi er to the
machine ground lug in the control cabinet. The bonding machine ground wire
should be the same AWG (mm) as the largest heater wire or sized per NEC or
IEC 60364 requirements.
Important:
Installing the keypad/display
If the keypad/display has been shipped loose,
mount it in a convenient location for easy
access, but not inside the control cabinet.
Mount the keypad/display using a fi eld-
supplied network phone wall plate. To mount,
slide the keypad/display onto the tabs on the
phone plate.
Note that the keypad/display requires an
ambient temperature range of 32 ºF to 122 ºF
(0 ºC to 50 ºC) to operate properly. Exceeding
these limits results in a poor reading or no
reading.
INSTALLATION
Control wiring and grounding requirements
