Burnham ALP150 - Manual (Page 64)

6
Figure
: Modular W
iring Diagram w/T
ekmar 265 Control
Tekmar 265 Based Control System (or equal)
Sequence of Operation
The
Tekmar 265 Control (or equal) can control either 3 modulating boilers or 2 modulating boilers and an Indirect W
ater Heater
. When a call for heat is
received by the
Tekmar 265 Control, the control will fire either one or more boilers in either parallel or sequential firing mode to establish a required reset
water temperature in the system supply main based on outdoor temperature.
The boilers will modulate based on an
Analog communication signal established
between the
Tekmar 265 Control and each boiler
’s MCBA
Control.
This signal is established by means of a pair of wires from boiler terminal strip to 265
Control utilizing a 500 OHM ¼ watt resistor bridging the conductor connections (the resistors are installer provided and available at any electronic parts store like Radio Shack, etc.).
The boiler(s) and system supply water temperature will be reset together to maintain what is needed to the system. When a call for
Indirect Hot W
ater is generated to the
Tekmar 265, the control will de-energize the zone pump control (ZC terminal), energize the Indirect pump and modulate
the boiler firing to establish a setpoint temperature in the main for the Indirect Heater using Priority
.
The
Tekmar 265 also controls each boiler
’s pump and a
post purge of leftover temperature in the boilers will occur at the end of the call for Indirect Hot W
ater
.