Trouble Shooting; To Simulate A Full Call For Cooling; To Simulate A Full Call For Heat; C-Trac2.1 Internal Operating Rules - EngA C-TRAC2 Installation, Operation And Maintenance Manual

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XXII. TROUBLE SHOOTING
:
NOTE

If there is to be an interruption of only the C-TRAC2.1 power such as by a time
clock shutdown at night, there cannot be any other load connected to the C-TRAC
terminals "H, A, E", or "K". If this wiring is not correct there may be about 18 volts
on any components attached incorrectly (when the C-TRAC2.1 has power turned off.)
This is the result of a feedback voltage which may cause certain output signals to
stay latched (i.e. it may keep a fan delay relay energized to keep fan running).

It will be necessary to allow time for the C-TRAC2.1 internal timers to complete
their timing steps if your simulation requires a change of modes or stages.

To Simulate a Full Call for Cooling

Set the switches to a discharge only control, and then open circuit the discharge sensor terminals "Q" and
"U".

To Simulate a Full Call for Heat

Set the switches to a discharge only control, and then jump the discharge sensor terminals "Q" and "U".

C-TRAC2.1 Internal Operating Rules

1.
Always satisfy the discharge temperature set point.
2. All reset signals only affect the discharge set point.
3. The control automatically selects the correct operating method to satisfy rule 1.
4. Selection of the operating method must follow these steps. Heat <> Economizer <> Mechanical
Cooling or Mechanical Cool/Econo.
5. The control must obey all time delays - minimum on, minimum off, inter-stage, operating mode, etc.

C-TRAC2.1 Set-Point Calculation

Only one option should be used at a time. If more than one option is used, the amount of total reset is
additive. This can push the calculated set point too far, make the room uncomfortable and can damage
equipment. (Discharge control dipswitch 1 should be "on" in all applications.)
1. Initial set point (as determined by the set-point dial).
+ PLUS
2. Optional calculated room reset demand as per set point.
+ PLUS
3. Optional calculated ambient reset demand (as per set point).
+ PLUS
4. Optional calculated BMS reset demand (4-20 ma. or 0-10 VDC) as per set point.
+ PLUS
5. Any other operating demand reset set point (e.g. night setback).
Example:
A room thermostat is trying to maintain the space temperature as per its set point. If the
room temperature is not as per the set point, the thermostat adjusts the discharge
temperature up or down to satisfy the condition. The amount of reset is proportional as to
C-TRAC2.1 MANUAL
Page i March 1999 R1