104
RT-SVX34F-EN
Diagnostics
The RTRM has the ability to provide the service personnel
with some unit diagnostics and system status information.
Before turning the main power disconnect switch “Off”,
follow the steps below to check the Unit Control. All
diagnostics and system status information stored in the
RTRM will be lost when the main power is turned “Off”.
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK HTB1
OR UNIT DISCONNECT SWITCH.
1.
Verify that the LED on the RTRM is on. If the LED is on
or blinking (2 blinks every 2 seconds). If so, go to step 3.
2. If the LED is not on, verify that 24 Vac is present
between RTRM J1-1 and J1-2. If 24 Vac is present,
proceed to Step 3. If 24 Vac is not present, check the unit
main power supply, check transformer (TNS1) and
fuse. If the LED is not on or blinking yet 24Vac is
present, the RTRM has failed and must be replaced.
3. If the LED is blinking, a diagnostic is present. If the LED
is on, certain diagnostics may still be present. Utilizing
“System Status/Diagnostics“, p.104
, check the
following system status:
•
Service status
•
Heating status
•
Cooling status
4. If any diagnostic is seen, refer to the appropriate
Diagnostics section for CV, SZ VAV, or Traditional VAV
units. Once the condition causing the diagnostic is
cleared, proceed to step 5.
5. If no diagnostics are present, use one of the TEST
mode procedures described in
“Test Modes“, p.55
to
start the unit. This procedure will allow you to check all
of the RTRM outputs, and all of the external controls
(relays, contactors, etc.) that the RTRM outputs
energize, for each respective mode. Proceed to Step 6.
6. Step the system through all of the available modes and
verify operation of all outputs, controls, and modes. If
a problem in operation is noted in any mode, you may
leave the system in that mode for up to one hour while
troubleshooting. Refer to the sequence of operations
for each mode to assist in verifying proper operation.
Make the necessary repairs and proceed to Steps 7 and
8.
7.
If no abnormal operating conditions appear in the test
mode, exit the test mode by turning the power “Off” at
the main power disconnect switch.
8. Refer to the individual component test procedures if
other microelectronic components are suspect.
System Status/Diagnostics
System status and/or diagnostics can be observed at the
ZSM, through ICS, or at the unit by using a DC voltmeter.
The LED on the RTRM module does not indicate whether
diagnostics are present or not. This RTRM LED is an
indicator that the RTRM has power, and it pulses during
the TEST mode.
Terminal locations
System Status / Diagnostics checkout
procedure (DC volt meter required)
The method described below to determine unit status or to
see if diagnostics are present assumes the Zone Sensor or
NSB panel is not within sight or close by or is not being
used. If a zone sensor is within sight however, DC readings
need not be taken - just look at the LED or display and go
to STEP 3.
1.
Measure and record DC voltage from J6-6 (common) to
each output: J6-7, J6-8, J6-9, and J6-10.
2. Using the data below, determine if each output is ON,
OFF, or PULSING.
All voltages are approximate - this is a sensitive circuit,
so the type of voltmeter used, sensor connections etc.
may all slightly affect the reading.
ON = 30Vdc if no NSB or ZSM with LED's is connected,
25 Vdc if NSB panel (BAYSENS119*) is connected, 2Vdc
if ZSM w/ LED's (BAYSENS110*, BAYSENS021*) is
connected.
OFF = 0.75 Vdc regardless of ZSM / NSB connection
PULSING (DIAGNOSTIC PRESENT) = A distinct pulsing
from 0.75 Vdc to 30 Vdc will be seen depending on the
type of meter used. Some meters may only pulse
between 20 and 30 volts DC.
3. Refer to the data in “What Outputs Mean” section to
determine course of action.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
Figure 65.
Terminal locations
