© 2007
D 161 - 08/07
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Relay 1 System Pump
In order to accommodate many different piping and pumping configurations, the
setpoint control is able to choose whether a “system” pump is required to operate at
the same time as Relay 1. This allows each manifold on a water temperature to have
a “system” pump when using zone valves or when using zone pumps together with
primary secondary piping. Only the manifold that has zones requiring heat should
have their “system” pump turned on.
When the setpoint control is connected to the tN4 boiler bus, the “system” pump is
the primary pump located on the tN4 system control.
When the setpoint control is connected to a tN4 mix bus, the “system” pump is
the mix system pump located on the tN4 system control or on a mixing expansion
module.
Zone
Group
Pump
tN4 Mix Bus
Setpoint
Control
Mix System
Pump
Boiler
tN4
System
Control
Zone
Manager
To turn on the “system” pump together
with Relay 1, set the Relay 1 Pump item
in the Adjust menu to On. This is the
factory default.
To turn on Relay 1 without the “system”
pump, set the Relay 1 Pump item in the
Adjust menu to Off.
Purging
When the setpoint control is used with a tN4 system control, the setpoint control
purges heat from the boiler into the setpoint zone if it is the last zone to shut off.
The length of the purge is dependent on time, the temperature of the boiler, and
the temperature of the setpoint load.
Priority
When the setpoint control is connected to a boiler tN4 bus, a priority setting is
available. When priority is set to On, the setpoint control has priority over the
thermostats. First, all heating thermostats are shut off. If there is sufficient boiler
capacity, boiler temperature zones are turned on in order of their tN4 address from
1 to 24. Second, boiler temperature second stage heating zones are turned on in
order of their tN4 address from 1 to 24. Last, all mixing outputs are increased up to
normal operating levels.
tN4 Address
When connected to other tN4 devices through a tN4 bus, the setpoint control is
automatically assigned a network address. The Address item in the Miscellaneous
menu displays the current address of the setpoint control. A total of 24 devices can
be connected to each tN4 bus.
If the 161 is operating as a member of a thermostat / setpoint only network, the
address consists of a device number with no bus number. If the 161 is not connected
to a tN4 network, the address item in the MISC menu is not available.
