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CNT-SVX08F-EN
value can also be used for controllers operating on a BAS. If both hardwired and communicated
setpoint values are present, the controller uses the communicated value. If neither a hardwired nor
a communicated setpoint value is present, the controller uses the stored default setpoints
(configurable using a service tool such as the Rover service tool).
ZN: Zone Temperature
The ZN analog input functions as the local (hardwired) zone temperature input. The controller
receives the temperature as a resistance signal from a 10 kW thermistor in a standard Trane zone
sensor wired to the analog input labeled ZN. A communicated zone temperature value can also be
used for controllers operating on a BAS. If both hardwired and a communicated zone temperature
values are present, the controller uses the communicated value. If neither a hardwired nor a
communicated zone temperature value is present, the controller generates a
Space Temperature
Failure
diagnostic.
The ZN analog input is also used to communicate timed override requests and cancel requests to
the controller for applications utilizing a Trane zone sensor with the on and cancel button option.
In addition, if the on button is pressed for more than five seconds, the controller initiates a Service
Pin message.
Outputs for SCC Applications
The MP501 includes four (4) outputs.
lists the outputs and their functions in SCC mode.
Table 3.
Outputs (SCC mode)
Output
Function
Binary output 1
Drive open or stage 1 (TRIAC)
Binary output 2
Drive close or stage 2 (TRIAC)
Binary output 3
Fan (relay)
Analog output (AO)
Controlled actuator (0–10 Vdc)
Binary Output 1/Binary Output 2
Binary outputs 1 and 2 are 24 Vac TRAIC outputs that are designed to switch ac common. They can
function in two different ways. They can drive a tri-state modulating actuator. For some
applications it may be more cost effective to use this type of actuator rather than a 0–10 Vdc
actuator.
shows a wiring diagram with the MP501 being used to control this type of
actuator.
Alternatively, binary outputs 1 and 2 can be used to control two separate binary outputs in stages.
The MP501 will first turn on stage 1 (binary output 1). Then, as the control loop senses a larger
demand, stage 2 (binary output 2) will be controlled on.
shows a wiring diagram with
the MP501 in this configuration.
Note:
The MP501 will control only one actuator. You cannot have both a 0–10 Vdc actuator and a
tri-state modulating actuator connected to the controller at the same time.
Binary Output 3
This binary output is a relay with a maximum current draw of 1 A. This relay will be energized based
on occupancy of the MP501. Typically, this relay will control a fan. The fan can be configured to
operate continuously or cycle on/off based on temperature. If configured as continuous, the fan
relay will be energized whenever the occupancy mode is occupied. The fan relay will be energized
only if the space temperature is calling for heating or cooling in the cycling mode. In unoccupied
mode, the fan relay always cycles according to the unoccupied temperature setpoints.
