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The low voltage side is equipped with the following terminals:
1) RC terminals (orange color) for an indoor room sensor for firing and modulating the
burner. (RC10 control standard supplied with GB142).
2) FA optional outdoor sensor terminals (blue color) connections (requires RC34 controller;
available Fall 2005).
3) WA T-T terminals (light green color) connections for optional conventional thermostat.
4) FW DHW tank sensor terminals (light gray color) for sensing tank water temperature.
(Tank sensor standard supplied with GB142).
5) EV terminals (red color) for connecting of an optional safety such as LWCO, manual
reset high limit or any other type of external limit circuit.
BC10 CONTROLLER
A BC10 control panel is installed in every GB142 which includes a diagnostic display, status
indicator lights, dials for DHW and maximum heater temperature as well as programming and
diagnostic access buttons. A detailed description of all diagnostic and status codes is provided
with the GB142 Installation and Service Manual.
RC10 ROOM CONTROLLER
A RC10 room controller is provided with every GB142 to provide indoor reset and pin point
precision control back to the BC10. The RC10 must be installed in a reference location for
indoor feedback to the GB142. The RC10 will control the modulation and heater water
temperature based on maintaining desired indoor comfort levels. The RC10 is typically placed
in the main living area for optimum comfort and accurate temperature control. Give careful
consideration to the placement of the RC10 sensor.
The use of the RC10 indoor room controller is shown in a number of diagrams to achieve
maximum comfort and efficiency from the product. Suggested timings of the post purge for the
boiler pump (PK) are shown on each wiring diagram.
Note:
Never
connect a RC10 control and a thermostat or end switch at the same time.
SPACE HEATING OPERATION:
The PK boiler pump operates and the burner fires on a call for heat from the T-T terminal or
from the RC10 controller. Use only T-T connections or RC terminals,
but do NOT use both at
the same installation
. Once the call for heat is satisfied, the PK pump continues to operate
through an adjustable programmable post-purge cycle before shutting down. The PK pump can
also set to operate continuously for up to 24 hours after the last call for heat.
DHW HEATING OPERATION:
A call for heat from the FW (DHW) sensor brings the control into DHW priority, shutting off the
PK pump, firing the boiler to maximum temperature and operating the PS pump. Internal logic
includes an anticipative DHW heating cycle with automatically adjusting post purge feature and
reduces burner modulation rate.
