AERCO Combination Control Panel (CCP) - Manual

COMBINATION CONTROL PANEL
MODEL CCP
Domestic Water/Space Heating
Multiple Boiler Controller
Concept
AERCO International recommends individual KC water
heating and space heating systems wherever possible.
Individual water heaters and boilers achieve maximum
efficiency and precise temperature control. However,
when factors such as existing indirect storage water
heaters, restricted fuel input, or space limitations are
conditions to be met, AERCO KC Boilers can be used in a
dual service role.
Combination System Description
In order to accommodate the requirements for both space
heating and the production of domestic hot water, multiple
KC style boilers can be used in a combination space
heating and domestic water heating plant. Boiler modules
are piped in a multiple boiler arrangement as they would
be in a multiple unit space heating plant. See Combination
Boiler Plant Sizing section for recommendations on num-
ber of modules required. The necessary number of mod-
ules for domestic water production are isolated from the
heating system in the supply piping by means of a nor-
mally closed two way motorized valve. An external hot
water storage generator is used to convert boiler water to
produce potable water through a closed loop coil. Upon
demand for domestic water, the isolated (combination
duty) boilers produce a constant temperature supply
(70.220F) by operating in the internal setpoint mode.
The AERCO Combination Control Panel (CCP) is an
accessory panel designed to work in conjunction with an
AERCO Model 168 Boiler Management System (BMS) to
control the firing of the combination boiler modules and
the associated accessories for domestic water production.
The CCP panel allows operation of the combination boiler
modules to produce domestic water through the external
generator coil, and activates the circulating pump between
the boilers and the coil. The CCP uses a simple tank
aquastat to start domestic water production. It allows
control of up to four KC Boilers (Boiler Control Code -6) in
the constant set point mode, and allows a transfer of the
motorized valve and the control of the modules to the
BMS when the space heating requires their added input.
By utilizing a CCP Panel in tandem with a Model 168
Boiler Management System, the KC Boilers efficiency will
be maximized. Only the required energy (input) for
domestic water will be used, and the heating plant can
operate at lowest required temperatures for space heating
to maximize condensing efficiency.
Domestic Water Mode
The tank aquastat, or domestic water demand device, is
wired to the CCP to signal a demand for domestic water.
The CCP supplies 12VDC to the dry contacts of the
domestic water demand device (aquastat). Upon a
demand for domestic water, the CCP enables the com-
bination boiler modules to begin firing to their internal
setpoint temperature. Each module will automatically
modulate its input to meet the requirement of domestic
water production. The closed motorized valve isolates the
normally higher temperature boiler water from the heating
system. The circulating pump between the combination
modules and the coil is activated simultaneously with the
combination modules. The boilers and pump will operate
continually until the domestic water aquastat is satisfied.
Heating Mode
The Boiler Management System (BMS) will activate the
heating plant and sequence/modulate the heating-only
boilers in the selected mode. When all dedicated heating
modules are operating at 100% input, the BMS will close
the Auxiliary contacts wired to the CCP Panel. The CCP
will then activate the motorized valve to open piping
between the heating system loop and the combination
boiler loop. The CCP supplies line voltage (120/1/60)
directly to the valve operator. The valve must be a three
wire control type with power open/power closed operator.
Operator timing on motorized valves should be in the 8 to
45 second range, and must be equipped with a dry con-
tact SPST N.O. end switch. When the valve reaches the
full open position, the dry contact end switch of the valve
will close, signaling the supply piping between the heat-
ing-only and combination boilers is open. This transfers
control of the combination modules percentage of firing
input to the BMS. The BMS will then add the combination
modules to the heating system, and modulate them to
their required input level. The boiler modules will be
sequenced at the adjusted percentage as set in the BMS.
As the added input from the combination modules allow
the heating load (setpoint) to satisfy, the auxiliary contacts
of the BMS will open. The motorized valve will then be