tekmar 284 Boiler Control - Manual (Page 20)

© 2014 284_D - 08/14 20 of 60 A Watts Water Technologies Company
Combustion Air (C.A.) Damper & DHW Recirculation Pump Settings
Auxiliary Relay ----------------------------------- -----------------------------------
The control includes an auxiliary relay that can be used either
for a combustion / venting device or a DHW recirculation pump.
Selection is made through the AUX RELAY item in the Setup
menu. Off is also available if there is no Auxiliary device.
DHW Recirculation Pump
When the Aux Relay is set to DHWR, terminals 43 & 44 operate
a domestic hot water (DHW) recirculation pump. Refer to the
Pump Operation section of this brochure for a description of
the DHW recirculation pump operation.
Combustion Air Damper
When the Aux Relay is set to DMPR, terminals 43 & 44 operate
a combustion air damper / fan motor or power vent motor. The
relay closes once an appropriate call (e.g. Heat) is received
& the control has determined that one or more boilers need
to be turned on.
Combustion Air (C.A.) Proof Call ------------------ ------------------
The C.A. Proof Call is used to prove a combustion air or venting
device. Boiler operation cannot occur until the proof call is
present. If the proof call is lost during operation, the boiler
plant is sequenced off.
Once the DMPR contact is turned on, a C.A. proof call must
be present before the C.A. proof delay has expired.
The C.A. proof call feature is enabled by setting the DIP switch
to the External C.A. Proof position.
A C.A. proof call can be provided by:
Contact Closure
A dry contact or 24 V (ac) signal is applied across the C.A.
Proof Call terminals 3 & 4.
Combustion Air Proof Delay ---------------------- ----------------------
The control includes a time delay that is associated with the
C.A. proof call feature in order to determine if the proof device
is functional. Once the DMPR relay closes, the control allows
for this time delay to receive the C.A. proof call. If the C.A.
proof call is not received within the delay time, the control will
display an error message.
Combustion Air (C.A.) Proof Call Test ------------ ------------
The control includes a C.A. proof call test in order to determine
if the proving device has failed. If the DMPR relay is opened,
the C.A. proof call should not be present after 4 minutes. If
the C.A. proof call remains, the control will display an error
message.
Combustion Air Delay ---------------------------- ----------------------------
If the C.A. proof call feature is set to OFF (DIP switch), sequencing
only occurs once a user adjustable time delay elapses.
Combustion Air Post Purge ---------------------- ----------------------
There is a fixed 15 second post purge of the C.A. relay after
the last boiler has turned off, or the appropriate call (e.g. Heat)
is removed. If there is a call still present once the last boiler
has turned off, the control can look at the error & determine
if sequencing is to occur in a “short” period of time. If the
control does anticipate staging, the DMPR relay will remain
on. Otherwise, the DMPR relay will be turned off once the 15
second post purge elapses.
Setting the Schedule
To provide greater energy savings, you can operate the
control on a programmable schedule. The schedule is stored
in memory & is not affected by loss of power to the control.
If a tN4 network is detected the control can become either a
schedule member or schedule master.
Control (CTRL) Schedule (tN4 present) ----------- -----------
The schedule only applies to the control. The control follows
its own schedule & the events are not communicated to tN4
thermostats.
Master Schedule (tN4 present) ------------------- -------------------
If the control is connected to tN4 thermostats, then the control
can operate on a master schedule. You can set up a maximum
of four master schedules on the tN4 Network. A master schedule
is available to all devices on the tN4 network. Master schedules
simplify installation since one master schedule may be used
by multiple devices.
To create a master schedule:
Assign the control to be a schedule master by setting the
Heat Schedule item in the Schedule menu to Master (MST)
1 to 4. After a master schedule is selected, a clock symbol
will appear in the View menu display. •
The 284 Setback /Off DIP Switch must be set to Setback
to access the Schedule Menu.
To follow a master schedule:
Assign the control to follow a master schedule by setting
the Heat Schedule in the Schedule menu to Member (MBR)
1 to 4.
Schedule Types ---------------------------------- ----------------------------------
The schedule type determines when the schedule repeats
itself. This control includes four different schedule types:
• 24 Hour: Repeats every 24 hours.
• 5-2: Repeats on a weekly basis. However, it breaks the week
into weekend followed by the weekdays. This reduces the
amount of schedule event settings.
• 5-11: Repeats on a weekly basis. However, it breaks the
weekend into Saturday & Sunday followed by the weekdays.
This reduces the amount of schedule event settings.
• 7 Day: Repeats on a weekly basis & allows for separate event
times for each day.
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