AERCO BMS 168 - Manual (Page 10)

Time Delay Between Boiler Starts:
A fixed, 30-second time delay between
boiler starts ensures smooth energy input
without spikes in electrical, gas, or venting
conditions.
A
UTOMATIC
S
YSTEM
S
TART
Automatic system start contacts for
controlling auxiliary equipment such as
pumps and dampers can be selected to
close between 32°F and 100°F outside air
temperature, eliminating the need for the
plant operator to turn auxiliary equipment on
and off.
M
INIMUM AND
M
AXIMUM
H
EADER
S
ET
C
LAMPING
The supply water temperature can be
clamped at a maximum high temperature or
minimum low temperature, to ensure that
the building temperature is optimal for the
greatest comfort.
Two Interlock Circuits
(Enable/Disable Contacts)
The BMS contains two normally-open
interlock circuits that require only a set of
dry contacts to enable or disable the boiler
plant. They can be used to monitor pumps,
combustion air dampers, or other equip-
ment. Out-of-limit conditions trip the
interlocks, shutting down the boiler plant,
and providing a high level of protection.
A
DJUSTABLE
O
FFSET
The Offset feature can allow the
temperature of the supply water to be offset
in 1° increments over a range of -50°F
below to +50°F above its current
temperature. This feature is employed for
night setback or morning warmup. The BMS
lets you select, over a 7-day period, the time
when the offset begins and ends.
C
ONTROL
O
F
A
UXILIARY
E
QUIPMENT
The auxiliary relay uses a dry set of
contacts to operate auxiliary equipment. For
example, when the boiler plant is at 100%
load, these contacts close and can start an
auxiliary boiler, or notify an energy manage-
ment system of a full-load condition.
F
AULT
A
LARM
S
URVEILLANCE
The BMS continually monitors its sensors
for opens and shorts and the interlock
circuits for opens. However, the BMS fault
alarm relay does not close or indicate a fault
when a boiler has failed. The fault alarm
circuit consists of a dry set of 120 VAC
contacts rated at 5 A.
S
IMPLE
I
NSTALLATION
The BMS operates from 120 VAC, 50 to 60
Hz, and uses Belden 9841 or equivalent
wiring between modules for control and
monitoring. The lightweight panel can be
mounted up to 200 feet from the boilers
when using pulse width modulation
communication.
R
UGGED AND
R
ELIABLE
The BMS is housed in a NEMA 13-grade
enclosure and operates in ambient tempera-
tures as high as 131°F (55°C).
P
OWER
-O
FF
M
EMORY
Most system configuration values are
retained in nonvolatile memory for up to 10
years. Date and time remain in memory for
approximately 30 days.
M
ODBUS
C
OMMUNICATION
The BMS can monitor or control C-More
Boilers using Modbus communication via its
RS485 port. It can also be monitored or
controlled by a Building Automation System
(BAS) or a PC connected to its RS232 port.
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