Diagnostics - Trane S*HF*20-75 Troubleshooting Manual

Diagnostics

There are four types of diagnostics:
1. (PMR) Partial System Disable, Manual Reset
2. (PAR) Partial System Disable, Auto Reset
3. (INFO) Information Only
4. (HO) History Only
The Troubleshooting Chart below list all of the possible failure modes with the following columns:
Used With: Diagnostic Displayed: The string displayed at the HI, associated module, and
"used with" info.
5. Reason For Diagnostic: The condition which caused the failure mode, and troubleshooting tips.
6. UCM's Reaction: The type of failure, and the unit's response to the failure w/additional information.
7. Reset Required: The conditions that must exist to clear the diagnostic.
Table 11: Diagnostics Troubleshooting Chart
DIAGNOSTIC
DISPLAYED
Auto Reset Return
Pressure Limit
Used With: Return Fan w/
Power Exhaust w/Statitrac.
Module: MPM
Auto Reset SA Static
Pressure Limit
Used With: VVDA units, or
CVDA/CVZT units with
supply air pressure sensor
installed.
Module: RTM
BAS Module
Communications Failure
Used With: BAS system
control is expected.
Module: BAS
RT-SVP07B-EN
REASON FOR
DIAGNOSTIC
Problem: The return
plenum pressure exceeded
the Return Plenum
Pressure High Limit
Setpoint (3.5 iwc non-
adjustable) continuously
for 1 second.
Check: Return/Outside
Damper, Exhaust Damper
linkage. Return Plenum
Pressure reading.
Problem: The supply air
static pressure exceeded
the SA Static Pressure High
Limit Setpoint for at least
one second continuously.
Check: SA Pressure Sensor
Assembly, Isolation
Dampers, ductwork, BAS
system control of VAV
Boxes.
Problem: The RTM has lost
communications with the
LCI or BCI.
Check: Check all unit
wiring and terminations
between the RTM and LCI/
BCI modules.
UCM'S REACTION
The unit will trip all outputs,
de-energize dx cooling,
staged heating, fans, etc.,
and will drive all analog
ouputs closed/stop fan
speed, dampers,
modulating heat, etc.
The Return Pressure High
Limit trip counter is
incremented.
The unit will trip all outputs,
de-energize dx cooling,
staged heating, fans, etc.,
and will drive all analog
ouputs closed/stop fan
speed, dampers,
modulating heat, etc.
The Supply Pressure High
Limit trip counter is
incremented.
All active commands and
control setpoints provided
by the network, through
the LCI or BCI, will be
cancelled and/ or ignored.
Setpoints will fall-back to
the default designated
sources, otherwise Human
Interface setpoints will be
used.
DIAGNOSTICS Menu
RESET REQUIRED
(PAR) An automatic reset
occurs when the return
plenum pressure drops
below the Return Plenum
Pressure High Limit
Setpoint, the IGV/VFD
have closed/stopped, and
15 seconds have elapsed
since the shutdown
command was issued.
(PAR) An automatic reset
occurs when the supply air
pressure drops below the
SA Static Pressure High
Limit Setpoint, the IGV/
VFD have closed/stopped,
and 15 seconds have
elapsed since the shutdown
command was issued.
(PAR) An automatic reset
occurs after
communication has been
restored.
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