User Manual

MC2: 04/23/13 Page 84 of 144
GF-131
AERCO Control System (ACS)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: [phone]
Installation, Operation, and Maintenance Manual
OMM-0081_0D
Table 5-2: Common Problems (Cont.)
Problem Possible Causes Solution
EMS cannot see ACS
• Incorrect address
• Incorrect Baud Rate
• Faulty wiring between EMS
and ACS.
• See RS232 MENU (paragraph 3.6).
• See RS232 MENU (paragraph 3.6).
• See Chapter 2. Check wiring polarity
and connections.
Boiler RAMP UP or
RAMP DOWN too slow
or too fast
• RAMP UP or RAMP DOWN
time needs adjustment.
• PID requires adjustment.
• Refer to CALIBRATION MENU
(paragraph 3.12) and check the RAMP
UP %/MIN or RAMP DOWN %/MIN
• Refer to TUNING MENU (para. 3.10).
HEADER TEMPERA-
TURE not reaching
Setpoint
• Deadband requires
adjustment
• PID requires adjustment
• Check HDR TEMP DEADBND in
TUNING MENU (paragraph 3.10).
Default = 5°.
• See TUNING MENU (paragraph 3.10).
Need to restore Factory
Default Settings.
• Too many setting changes.
• Go to RESET DEFAULTS option in
CALIBRATION MENU (paragraph
3.12)
Boilers over-shooting
setpoint or tripping
aquastat
• Header sensor not installed
correctly
• PID setting require adjustment
• Adjustable aquastat set too
low
• System pumps are shut down
and not controlled by or
interlocked with the ACS
• Check header sensor connections and
installation.
• Adjust PID settingsin TUNING MENU
(paragraph 3.10).
• If aquastat is set lower than 200°F,
reset it to 220°F.
• If system pumps are shut down, check
start and stop temperatures on energy
management system. They should
correspond to those set in the ACS. In
addition, interlock wiring can be run
between the ACS and energy
management system to disable the
ACS pumps when pumps are not
running.
Modbus Network faults
encountered. Boiler
plant not operating
• ACS or boilers not properly
configured for Modbus
communication.
• Bias and/or termination not
activated.
• Refer to Modbus Communication
Manual GF-114 for C-More control or
GF-115-C for BCM control on Modulex
boilers. Check all wiring connections
and software menu settings.
• Activate termination in last boiler.
Activate bias on ACS for BCM control
or in last C-More control.
Percent of Load starts
to rise and suddenly
drops to zero.
• Bias Switch and/or termination
resister not activated at either
the boiler or the ACS.
• Refer to section 2.6 to 2.9 in this
manual.