Sequence Of Operation: Tracer Zn010 And Zn510; Binary Inputs - Trane UniTrane Installation, Operation And Maintenance Instructions

Start-Up

Sequence of Operation: Tracer ZN010 and ZN510

Note: This section applies only to units with a Tracer ZN010 or ZN510 controller.
Power-Up Sequence
When 24 Vac power is initially applied to the Tracer ZN010 or ZN510, the following sequence occurs:
1. All outputs are controlled off.
2. Tracer ZN010 and ZN510 reads all input values to detemine initial values.
3. The random start time (0-25 seconds) expires.
4. Normal operation begins.
Entering Water Temperature Sampling Function
Both Tracer ZN010 and ZN510 use an entering water temperature sampling function to test for the
correct water temperature for the unit operating mode. For all applications not involving
changeover, the water temperature does not affect unit operation.
The entering water temperature sampling function opens the main hydronic valve, waits no more
than three minutes to allow the water temperature to stabilize, then measures the entering water
temperature to see if the correct water temperature is available.
The entering water must be five degrees or more above the space temperature to allow hydronic
heating and five degrees or more below the space temperature to allow hydronic cooling.
If the correct water temperature is available, the unit begins normal heating or cooling operation.
If the measured entering water temperature is too low or high, the controller closes the valve and
waits 60 minutes before attempting to sample the entering water. Refer to
Table 15. Unit mode as related to water temperature
Unit Type
2-pipe changeover
4-pipe changeover
2-pipe heating only
2-pipe cooling only
4-pipe heat/cool

Binary Inputs

BIP1: Low Temperature Detection Option
The factory hard wires the low temperature detection sensor to binary input #1 (BIP1) on the Tracer
ZN010 and ZN510. The sensor defaults normally closed (N.C.), and will trip off the unit on a low
temperature diagnostic when detecting low temperature. In addition, the Tracer ZN010 and ZN510
control unit devices as listed below:
Note: See
86
EWT Sensor Required?
Yes
Yes
No
No
No
Fan: Off
Valves: Open
Electric heat: Off
Damper: Closed
"Diagnostics, " p. 107
Coil Water Temperature
COOLS if: Space temp - EWT ≥ 5°F
HEATS if: EWT - space temp ≥ 5°F
COOLS if: Space temp - EWT ≥ 5°F
HEATS if: EWT - space temp≥ 5°F
Hot water assumed
Cold water assumed
Cold water assumed in main coil
Hot water assumed in aux. coil
for more information.
Table 15.
UNT-SVX07B-EN