tekmar 284 Boiler Control - Manual (Page 12)

© 2014 284_D - 08/14 12 of 60 A Watts Water Technologies Company
Setpoint operation is dependant on the application mode
setting.
If the Application Mode is configured for Outdoor Temperature
Reset (RSET) or Energy Management System (EMS), the control
provides heat for an additional setpoint load. The control does
respond to a Heat Call from a space heating system.
If the Application Mode is configured for Setpoint (SETP), the
control provides heat only for the setpoint load. The control
does not respond to a Heat Call for space heating.
Indirect Domestic Hot Water (IDHW) operation is available
during setpoint operation.
Set point Call ------------------------------------ ------------------------------------
A Setpoint Call is required in order for the control to provide
heat to a setpoint load, such as a spa, pool or snowmelt load.
Once the control registers a Setpoint Call, it will display the
“Setpoint” icon under the Calls in the display. A setpoint call
can be provided in two ways:
Contact Closure
A dry contact or 24 V (ac) signal is applied across the Setpoint
Call terminals 9 & 10.
tekmarNet ® Setpoint Control with Sensor
A Setpoint Call is provided through the tekmarNet ® system.
This can be done through the tN4 Boiler Bus terminals with a
tekmarNet
® setpoint device such as a Setpoint Control 161.
Boiler Target Temperature During a Setpoint Call ---- ----
When a Setpoint Call is present, a boiler target is
determined.
When using a Contact Closure, the boiler target is set to the
SETP Setpoint setting.
When using a tekmarNet
® Setpoint Control, the boiler target
is set to the devices Exchange Supply setting.
If there are multiple devices calling for heat, the boiler target
is set to the highest temperature requirement.
Setpoint During UnOccupied
When using a Contact Closure, a second SETP Setpoint setting
is available for the Unoccupied periods.
DIP Switch must be set to Setback to view UnOccupied
items.
During the Away Scene, Setpoint Calls are ignored.
Setpoint Mode ------------------------------------ ------------------------------------
The control has a Setpoint Mode setting that selects whether
or not setpoint heating is operational.
OFF
Setpoint operation is not provided. All Setpoint Calls are ignored.
If this mode is selected while setpoint operation is underway,
all setpoint operation ceases.
ON
Setpoint heating is provided. All Setpoint Calls are responded to.
Operation is dependant on the Primary Pump During Setpoint
operation setting.
•
•
•
•
Primary Pump During Setpoint ------------------ ------------------
This setting selects whether or not primary pump operation is
required during setpoint heating.
OFF
The primary pump does not turn on during setpoint heating. It
is assumed that the setpoint load pump will provide adequate
flow through the setpoint load & the boiler system loop.
Setpoint
Primary
ON
The primary pump turns on during setpoint heating.
Primary
Setpoint
Setpoint Priority ---------------------------------- ----------------------------------
This setting selects whether or not priority of setpoint over
space heating is required. Setpoint priority stops or limits the
delivery of heat to the space heating system while the setpoint
load calls for heat. This allows for quick recovery of the load.
OFF
Setpoint priority is not provided. The primary pump can operate
when a Heat Call is present. Heating zones are unaffected by
setpoint heating.
ON
Setpoint priority is provided & is dependant on the type of
space heating zones & whether or not the primary pump is
required to operate during setpoint heating.
For non-tN4 space heating, the primary pump shuts off to
provide priority. If the primary pump is required to operate for
setpoint heating, priority requires the use of an external relay
to force the heating zones off.
For tN4 space heating, the primary pump can operate when a
Heat Call is present. If the boilers are unable to maintain the
boiler target temperature, the tN4 zones are sequentially shut
off using tN4 communication to provide priority.
Setpoint Operation