2-9
BOILER SYSTEMS AND OPERATION
SL 30-175, SL 45-260 MODULATING GAS BOILERS
2.6.6 Unoccupied Mode
users can further reduce energy consumption by switching the boiler to the
unoccupied mode during holidays or other away periods.
While in the unoccupied mode, the dHW load is turned off, while space Heating
loads for which outdoor reset is activated will drop both the circulating water and
the indoor setpoint temperature parameters to 50°F. set Point controlled loads
are not adjusted through this process, to avoid the potential for boiler cycling as
there is no linkage with the relevant thermostat.
on the main
User Setup
Menu, select
“Occupancy Status”
, then toggle between
Occupied
(top button) and
Unoccupied
(lower button) as desired.
2.6.7 Summer Shutdown
during the installer set up process, a cut-off level for outdoor temperature can be
selected - to curtail any further space heating. this is typically used to turn off an
outdoor reset enabled load once the outdoor temperature reaches a threshold
level e.g. 60°F. the load will be automatically reactivated once the weather
returns to levels below the selected threshold. use of this feature with a value 5°
- 10°F below the
Indoor Setpoint Temperature
is strongly recommended to avoid
short cycling of the boiler during very marginal heating conditions.
From the main installer setup Menu, select
“Heat Load Configuration”
, then
“Configure Load (use the load number tagged as Space Heating)”
, and drop
down to “summer shutdown”. Press enter to select, then use the keys to move
the threshold temperature to the desired level, and press the centre key again to
record. the controller must receive a valid signal from the
tekmar 070
outdoor
sensor, supplied with the boiler, to operate.
2.6.8 Remote / Subordinate Mode
installers have the option of placing the control of the boiler under an external
electronic controller (such as a
tekmar 265
). Connections are provided to receive
a 0-10vDC or 4-20 mA signal for throttle management. The default configuration
is 0-10vdC; to switch over to 4-20 ma, remove the electrical box corner cover
and the circuit board cover to provide access to the slotted clearance hole on the
lower right corner of the control circuit board; use needle-nose pliers to move the
plastic jumper tab from the left two terminals to the right two terminals. Where
the iBC controller senses a signal on the remote connections, it automatically
subordinates its internal throttle logic, and adopts the external signal. in such
slave mode, temperature management is also surrendered to the external
controller’s sensors. the installer only enters Maximum Boiler supply and on/off
differential temperatures; the boiler will respond to these as high limit switches.
From the main installer setup Menu, select
“Define Load (with desired #)”
, then
locate and enter
“External Control”
. Next, configure the load with the Maximum
and differential temperature values.
Summary of Contents for SL 30-175
Page 76: ...NOTES...
