3
III) LOCATION & MOUNTING
The P2621-NO2/VC can be used to monitor up to 10,000 square feet of undivided area.
It can be used as a self-contained, stand-alone control or as part of a multi sensor Control
system. If the airflow is not uniform or if the area to be monitored is unusual, then the
area by each unit should be appropriately reduced.
Select an appropriate mounting location in an area of heavy traffic flow, away from drafts
and where the vent holes on the bottom of the unit will not be blocked. Mount the unit
with four (4) screws using the external mounting feet provided. The unit should be at a
convenient height, typically five (5) feet above the floor.
IV) INSTALLATION & WIRING
After mounting the unit(s) as described above, connect the power and relay wires as
shown in INSTALLATION DIAGRAM page 9 of this manual. The power circuit and
Control circuit of the unit(s) must be wired with 18 AWG or heavier copper wire. A
multiple sensor installation requires only a simple series Connection of the fan Control
relays. This feature allows for maximum flexibility in system design and installation.
Zoned systems are easily created when several sets of fans need to be controlled
independently.
1.
Be sure to turn OFF power to fan Control system and 24 VAC power supply
before wiring and Connections are made.
2.
Open the enclosure using the provided hex-key. The Control card is mounted on
the inside of the enclosure door. A terminal block for electrical Connections is
located on the back panel of the monitor. The terminals are marked for power
input and relay Connections.
3.
The wiring must enter the P2621-NO2/VC enclosure through the two (2)
electrical openings provided on the unit with conduit fittings.
4.
Connect 24 VAC power supply to terminals T1 and T2 of the terminal block.
Each P2621 unit requires 12 watts of power for proper operation.
5.
Connect the relay (Control) Contacts K1 and K2 in series with the coil of the
ventilation fan control, intermediate relay, or K1 and K2 of the next unit (for
multiple units configuration). NOTE: the P2621-NO2/VC must be wired so
that the fans are ON when the relay contacts K1 and K2 are open.
6.
OPTIONAL ALARM RELAY- Connect the optional relay (alarm relay) Contacts
K3 and K4, if so equipped, as shown in Installation Diagram page 9 of this
manual.
7.
Verify that the wiring to each unit is correct.
