User Guide

27
EM-40-SM Service Manual
Applications
Mode 6 and 7 – External Target Temperature Input and Setpoint Operation
M
ode 6 – External Target Temperature Input and
Setpoint with Parallel Piping
The control receives a heat demand provided from an
external target temperature input signal. The control turns
on the boiler pump and operates the boiler to maintain the
target temperature at the boiler outlet sensor. The control
receives a setpoint demand from a DHW aquastat. The
control turns on the boiler pump and operates the boiler to
maintain the setpoint boiler target temperature at the boiler
outlet sensor whenever a setpoint demand is present.
Note: An external relay is required to operate the DHW
pump and provide DHW priority if required by disabling
the boiler pump.
M
ode 7 – External Target Temperature Input and
Setpoint with Primary – Secondary Piping
The control receives a heat demand provided from an
external target temperature input signal. The control turns
on the boiler pump and operates the boiler to maintain the
target temperature at the boiler supply sensor. The control
receives a setpoint demand from an external control. The
control turns on the boiler pump and operates the boiler to
maintain the setpoint boiler target temperature at the boiler
supply sensor whenever a setpoint demand is present.
BTC
Mode 6
EMS
0-10 V (dc)
Boiler Inlet Sensor
Boiler
Outlet
Sensor
Relay
BTC
Mode 7
0-10 V (dc)
tN4 System
Control
Boiler
Outlet
Sensor
Boiler
Supply
Sensor
Boiler Inlet Sensor
Relay
BTC
Mode 6
EMS
0-10 V (dc)
Boiler Inlet Sensor
Boiler
Outlet
Sensor
Relay
BTC
Mode 7
0-10 V (dc)
tN4 System
Control
Boiler
Outlet
Sensor
Boiler
Supply
Sensor
Boiler Inlet Sensor
Relay