Catalogue

46 UNT-PRC001-EN
Controls
calculating the required heating or cooling capacity (0–100%) according to the measured zone
temperature and the active zone temperature setpoint. The active zone temperature setpoint
is determined by the current operating modes, which include occupancy and heat/cool modes.
• Disc
harge air temperature control— is the backup mode that runs only if there is not valid
zone temperature. In this mode, the active space temperature setpoint is used as the discharge
air temperature setpoint.
Important: Th
is is not a normal operating mode. The source of the invalid zone temperature
needs to be corrected to restore normal operation.
** 'Generic' i/o - if there is unused i/o the user may create a new point to reference the i/o. But there is no dedicated 'generic'
i/o like on ZN
Binary inputs -- t
here is also a defrost and fan status (for 1,2,3 speed fans) for UC400 and ZN520.
The ECM fan does not use the Binary inp
ut for fan status but gets the info over IMC from the ECM.
ZN520 also had a binary input for fan status. ZN520 also had de
frost but it was wired directly to the compressor (IOP
explains this).
Table 35. Controller input/output summary
ZN010 ZN510 ZN520 UC400
Binary Outputs X
3-Speed Fan XXXX
2-Position Hydronic Valve X X X X
2-Position Fresh Air Damper X X X
1-Stage Electric Heat X X X X
3-Wire Economizer Damper X X
3-Wire Hydronic Valve XX
2-Stage Electric Heat XX
Reheat (hydronic or electric) X X
Generic X X X **
Binary Inputs
Condensate Overflow Detection X X X X
Low Temperature Detection XXXX
Occupancy XXXX
Generic Input X X X **
Analog Inputs
Zone Temperature X X X X
Setpoint XXXX
Fan Mode: Auto, High, Medium, Low X X X X
Entering Water X X X X
Discharge Air XXXX
Outside Air XX
Generic X**
Analog Outputs
Variable speed fan X
Field supplied analog valves X
Note: The generic input and output are for use with a Tracer Summit system only.
Table 36. Controller function summary
ZN010 ZN510 ZN520 UC400
Control Functions
Entering Water Temp. Sampling (Purge) XXXX
Auto Changeover XXXX
Fan Cycling X X
Warm-Up XXX
Pre-Cool XXX
Data Sharing (Master/Slave) X X
Random Start XXXX
Dehumidification XX
Single Zone VAV X
Staged Capacity (2-Stage Electric Supplementary) X X
Other Functions
Manual Test X X X in TU
Maintenance Timer XXXX
Setpoint Limits XXXX
Sequence of Operation
UNT-PRC001-EN.book Page 46 Tuesday, May 8, 2012 10:54 AM