SystemAir fantech ECHO 2800Xi Series, Installation, Operation And Maintenance Manual, Page: 7 / 19

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Unit components and electrical connections (Cont'd)
Power IN
7/8" - 1"
knockout
Control IN
7/8" - 1"
knockout
The main power connection of this unit must be preceded by an all pole circuit breaker. The connection from this circuit breaker to the unit main
power knockout must be run in flexible conduit (field supply & specify) for the reason that the unit electrical connection box is mounted on a hinged
access panel used to service the fan motors.
Main power & circuit breaker connection
This unit is equipped with two (2) electronically-commutated (EC) fan motors referred to as SF & SAF (supply air/fan) or EF & EAF (exhaust air/fan)
(see unit wiring diagram). Both fan motors can be accessed by opening the smaller hinged access panel.
EC fan motor assemblies
The speed of these EC fan motors are controlled by analog outputs from the unit controller. With feedback from the unit’s built in pressure
transducer modules, the controller will modulate the fan speed in order to maintain the airflow set point. This method of controlling the unit airflow is
called Constant Air Volume (CAV). More details in the “Pressure transducer modules” section.
As mentioned in the previous section, this unit is equipped with two (2) pressure transducer modules referred to as Pressure transducer exhaust
(PTE) and Pressure transducer supply (PTS) (see unit wiring diagram). They are located inside of the unit on the return air side and can be accessed
by opening the larger hinged access panel.
Pressure transducer modules
Each module has two (2) pressure transducer.
The first pressure transducer on the PTE module measures the pressure drop over the inlet ring of the exhaust air fan in order to control the fan
speed. The second one measures the pressure drop over the supply air filter for the dirty filter alarm.
The first pressure transducer on the PTS module measures the pressure drop over the inlet ring of the supply air fan in order to control the fan
speed. The second one measures the pressure drop over the exhaust air filter for the dirty filter alarm
More details on the pressure transducers in the “Airflow control” & “Alarm handling” section.
If EFD dampers and/or a BPM module has been supplied with the unit and mounted as per their provided installation instruction, the electrical con-
nection can now be made.
The outdoor air damper is connected to terminal TB3 10-12 (see unit wiring diagram) using the harness provided with the accessory.
The exhaust air damper is connected to terminal TB3 10-14 (see unit wiring diagram) using the harness provided with the accessory.
The BPM module is connected to terminal TB3 10-12 (see unit wiring diagram) using the harness provided with the accessory.
Wiring the dampers & the BPM module actuators
The dampers and/or BPM module must be installed and wired back to the electrical connection box as indicated above for the unit to
function properly. Ensure this is done before proceeding.
Unit components and electrical connections (Cont'd)