Trane LO manual Tracer ZN.520, Tracer Summit Communication Wiring, Sequence of Operations

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Tracer Summit®

Tracer Summit®

Communication

Wiring

Tracer® ZN.520

Tracer® ZN.520

Tracer® ZN.520 is a communicating or standalone device. It is easily accessible in the control end panel for service. The control end panel is on the end opposite the piping.

Sequence of Operations

OFF: Fan is off; control valve options and fresh air damper options close. The low air temperature detection option is still active.

Auto: Fan speed control in the auto setting allows the modulating (3- wire floating point) or 2–position control valve option and three-speed fan to work cooperatively to meet precise capacity requirement, while minimizing fan speed ( motor/energy/acoustics ) and valve position (pump energy, chilled water reset ). As the capacity requirement increases at low fan speed, the water valve opens. When the low fan speed capacity switch point is reached, the fan switches to medium speed and the water valve repositions to maintain an equivalent capacity. The reverse sequence takes place with a decrease in required capacity.

Low/Med/High: The fan will run continuously at the selected speed and the valve option will cycle to meet setpoint.

For Tracer® ZN.520 controlled units that will interface with the Trane Tracer Summit® building management system, terminate the commu- nication wiring in the control box at the designated terminals on the board. Reference the unit wiring diagram or submittals.

Ground shields at each Tracer® ZN.520, taping the opposite end of each shield to prevent any connection between the shield and anther ground. Refer to Trane publication, CNT-IOP-2 Installation, Operation and Programming Guide, for the communication wiring diagram.

Communication wire must conform to the following specification:

1)Shielded twisted pair 18 AWG

2)Capacitance 23 (21-25 ) picofarads ( pF ) per foot

3)Listing/Rating – 300V 150C NEC 725-2 (b) Class 2 Type CL2P

4)Trane Part No. 400-20-28 or equivalent, available through Trane BAS Buying Group Accessories catalog.

UNT-IOM-6

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Page 59
Image 59
Trane LO manual Tracer ZN.520, Tracer Summit Communication Wiring, Sequence of Operations