Trane SCXG-SVX01B-EN Maintenance diagnostics, Emergency Stop, Entering Cond WaterTemp Sensor Fail

Maintenance diagnostics

Reset Required: (PAR) An automatic reset occurs after communication has been restored.

Emergency Stop

Problem: The emergency top input is open.

Reason for Diagnostic: An open circuit has occurred on the emergency stop input caused either by a high duct temp t- stat trip, or the opening of field-provided contacts, switch, etc.

UCM Reaction: Off or close requests are issued as appropriate to the following functions;

a. Compressor staging/chilled water cooling control

b. Heat operation

c. Supply fan control and proof of operation

d. Exhaust fan control and proof of operation.

e. Exhaust actuator control f. Outside air damper control

g. OnVAV units, IGV/VFD control

Reset Required: (PMR) A manual reset is required after the emergency stop input recloses. The diagnostic can be reset by the HI.

Entering Cond WaterTemp Sensor Fail

Problem:

Activation Conditions: temperature < - 50°F or temperature > 209°F, and unit configured for water cooled condenser

c.Time to React: 10 sec <T < 20 sec

d.DiagnosticText (Human Interface Display) “ENT CONDWATERTEMP SENSOR FAIL”

e.Actions to be Initiated: A “Lockout All Ckts ” request is issued to the “Compressor Staging Function”

f.Reset: An automatic reset occurs after the entering condenser water temperature input returns to within range continuously for 15 seconds.

Entering Water Temp Sensor Fail

a. Data used (module, packet, byte, bit): WSM, 01,18,05

b. Activation Conditions: temperature < - 50°F or temperature > 209°F, and unit

configured with water cooled condenser and/or economizer c.Time to React: 10 sec <T < 20 sec

d.DiagnosticText (Human Interface Display) “ENTERINGWATERTEMP SENSOR FAIL”

e.Actions to be Initiated: A “Disable Water Side Economizer” request is issued to “Water Side Economizer Temperature Enable Function”

f.Reset: An automatic reset occurs after the Entering WaterTemp. input returns to within range continuously for 10 seconds.

EvapTemp Sensor Failure - Circuit 1, 2, 3, or 4

Problem: The evaporator temperature sensor (ckt #1, 2, 3, or 4) is out of range.

Check: Sensor resistance should be between 830 ohms (200°F) and 345.7Kohms (-40°F). If so, check field/unit wiring between sensor and MCM/SCM.

Reason for Diagnostic: The unit is reading a signal that is out of range for the circuit #1 evaporator temperature sensor input (temp < -55°F or temp > 209°F).

UCM Reaction: The coil frost protection function for the refrigeration circuit (#1, 2, 3, or 4) only is disabled.

Reset Required: (PAR) An automatic reset occurs after the #1, 2, 3, or 4 evap temp input returns to its allowable range for 10 seconds.

G

GBAS 0-5 VDC Module Comm Failure Problem: The RTM has lost communication with the GBAS module.

Check: Field/unit wiring between RTM and GBAS.

Reason for Diagnostic: The RTM has lost communication with the GBAS module.

UCM Reaction: The UCM will initiate the following actions;

a. If the demand limit input was closed prior to the communications loss, then the demand limit commands issued to the heat operation function (if applicable) and the compressor staging/

chilled water cooling function will be cancelled.

b. If any of the GBAS setpoint control parameters are the HI-selected setpoint sources, then those setpoints will revert to the default HI setpoints.

c. Any active GBAS output control parameters will be ignored.

d. A failsafe function in the GBAS module will cause all GBAS outputs to be zeroed and deenergized.

Reset Required: (PAR) An automatic reset occurs after communication has been restored.

H

Heat Failure

Problem: The heat has failed. (Electric heat unit)Typically, this is because the electric heat section became too hot.

Reason for Diagnostic: The heat fail input on the heat module was closed:

a. for more than 80 seconds,

b. for ten consecutive occurrances (each lasting five seconds or more) within a 210 second period.

UCM Reaction: An information only diagnostic is set.

Reset Required: (INFO) An automatic reset occurs after the heat fail input remains open for 210 seconds continuously.

Heat Module Auxilliary Temperature Sensor Fail

Problem: The heat mod aux temp sensor input is out of range.

Check: Sensor resistance should be between 830 ohms (200°F) and 345.7 ohms (-40°F). If so, check field/unit wiring between sensor and heat module.

Reason for Diagnostic: At least one enabled unit function has the heat module auxillary temperature input designated as its sensor, and the unit is reading a signal that is out of range for this input (temp < -55°F or temp > 209°F).

UCM Reaction: The functions that

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