Johnson Controls York Smart Equipment SC-EQ, Руководство по установке

Страница: 34 / 52

JOHNSON CONTROLS
34
FORM 450.50-N1
ISSUE DATE: 08/19/2019
SECTION 3 - TROUBLESHOOTING
Equipment Network
EQ BUS -
A Green LED that indicates the commu-
nication activity between the SC-EQ and the chiller
Microboard. The SC-EQ acts as the Master in this net-
work and issues data requests to the chiller Microboard.
The EQ BUS LED blinks as it receives a valid response
from the chiller Microboard. The data is requested one
parameter at a time so the blink rate is almost constant.
There are two additional LEDs on the Equipment Port
to aid in diagnosing communication problems with the
microboard.
ERX - A Green LED that illuminates when the SC-EQ
is Receiving data from the microboard.
ETX - A Red LED that illuminates when the SC-EQ is
Transmittinging data to the microboard.
Normal Sequence - The Red ETX LED is illuminate
when the SC-EQ sends a request for data to the chiller
microboard. The microboard Receive LED should then
illuminate. The microboard should then illuminate it's
Transmit LED as it sends the requested data and the
Green ERX LED on the SC-EQ should illuminate.
If the SC-EQ ETX light illuminates and the micoboard
Receive LED illuminates but no response is transmit-
ted from the microboard check that the chiller address
is set to 1. For microboards with a rotary switch set to
0 which is interpreted as a 1. If the address is set in the
software, then it should be set to 1.
Fault
A Red LED that indicates a problem with the SC-EQ
Firmware or indicates the status during a program update.
Power-Up -
The LED blinks while the SC-EQ is ini-
tializing and perfroming self checks.
Normal Operation - The LED should normally be OFF.
Firmware Update - The LED blinks at a 100 ms cycle
while the Firmware is updating.
Unable to Load Firmware -
The LED blinks at a
500ms cycle to indicate that the SC-EQ could not load
a firmware update. Try loading the firmware update on
to another USB thumb drive and perform the update
again.
Firmware Validation Failure -
The LED blinks at a
1 second cycle whenever the SC-EQ fails to validate
the firmware at intial power up or after a firmware up-
grade. Try cycling power to the SC-EQ and updating
the firmware again.
Firmware Programming Required -
The LED is ON
solid indicating no firmware is present. A firmware up-
date should be performed to remedy this.
MULTIMETER CHECKS OF THE BAS PORT
If the SC-EQ board is connected to a BAS bus but the
BS BUS LED is off steady then the SC-EQ board is not
likely seeing any valid communications occurring on
the BAS bus. Simple voltage measurements with a DC
voltmeter can be made on the SC-EQ board and BAS
communication bus to help diagnose the problem.
1. Remove the BAS plug from the SC-EQ J12.
2. Note the position of the BAS End Of Line (EOL)
Switch S2. (If the SC-EQ is not the EOL device,
the EOL switch must be OFF) If it is the EOL then
set the EOL to ON temporarily for these tests.
3. Measure the voltage between the + and – pins on
the BAS Bus Terminal Block as shown in the top
portion of Figure 39 on page 35 . The positive
lead of the voltmeter should be on the + pin of
the block and the negative lead of the voltmeter
on the – pin of the block. The voltage reading can
fall in the range of (0.38 VDC to 0.47 VDC). The
reading should be steady and only changing by a
couple of millivolts at the most. If the reading is
within the range of (+0.38 VDC to +0.47 VDC)
that is an indication that the BAS transceiver on
the SC-EQ board is not damaged. If the volt-
age reading is out of the range given by a large
amount, the transceiver or its associated circuitry
may be damaged. Again verify that switch S2
(BAS EOL) is in the “ON” position during the
measurement otherwise the voltage readings
are out of the given range.
4. If the reading in step 3 is within the given voltage
range then return switch S2 (BAS EOL) to its prop-
er position and connect the BAS terminal block
plug back into the BAS terminal block J12 on the
SC-EQ board. Take another VDC voltage reading
now on the BAS plug between the + and –wire con-
nections as shown in the bottom portion of Figure
39 on page 35 . If the BAS bus is connected to
a JCI BAS bus with proper EOL terminations set
then the voltage range should be steady and in the
(0.38 VDC to 0.47 VDC) voltage range if NO