INSTALLATION AND OPERATION INSTRUCTIONS
2-6
SL 30-175, SL 45-260 MODULATING GAS BOILERS
the pump remains on until the loop drops ½ the differential below the new load
target temperature. note: if there is no place to sink heat during such Circ. mode,
this phase will continue indefinitely, affecting heat delivery.
thermal shock avoidance is key. Wherever two or more loads are used, and
settings could permit supply temperature differences greater than 20°F, external
3-way motorized or injection mixing is called for.
a thermal shock avoidance routine is employed to avoid undesirable effects of
large temperature swings: the hot load pump remains on until the boiler’s return
water sensor detects temperature stability - to sink excess heat. For example,
upon satisfaction of a dHW call the dHW load pump will remain running until the
boiler return water temperature falls to the dHW tank target temperature. this
deposits legacy heat from the primary loop into the water tank before activation
of a cooler load.
always ensure that loads sensitive to high temperatures are protected using
appropriate means - e.g. a three way mixing valve set to restrict entering water
temperature to 130°F.
2.5.6 - Error Mode
the controller continually checks sensors to see that they are operating within
normal parameters. if sensors indicate the boiler is operating outside it limits, it
will declare an error condition. two types of error conditions can occur:
•
Soft Errors:
result when an abnormal condition exists which does not present
an immediate safety hazard. the boiler enters an extended purge, followed
by the error cycle of 5 minutes for all conditions other than Maximum ignition
Trials (a modified Hard Error which locks out for 1 hour after 3 unsuccessful
ignition attempts). Following the purge, the fan and pump are stopped until
the end of the error cycle. normal operation then resumes.
•
Hard Errors:
result when a condition exists that may be a safety hazard.
the boiler enters an extended purge then the fan and pump are stopped.
the boiler is in a lockout, and must be checked and restarted by a service
technician.
With software versions 3.10.0 and higher, the boiler offers an error status signal
feature.
Please see IBC Technical Note: Boiler Status – Analog Output.
see
Section 5.3.1 Control Panel
for a list of hard and soft errors and their
likely causes. note that other problems such as disconnected wires or defective
sensors may be the cause of the error. Always check connections and wiring first.
otHer oPerating Features
2.6.1 Prioritization
the control module hosts a scheduling routine to manage the boiler’s operation
when more than one load has been defined. Load scheduling allows adjustable
prioritization across loads 1, 2, and 3, with settable values from 20 to 90. note:
these values do not represent percentages and do not add up to 100; rather, they
are used to set relative importance of loads. to avoid instability, do not equal
priorities - spread loads by 10 points or more. a setting of “90” gives absolute
priority; otherwise, the difference between settings equals the run time (in
minutes, for the initial cycle) of the higher load setting before switch-over to the
simultaneously calling load, e.g. dHW with priority set to 80 will run for approx.
35 min. before switching to a clashing load set with priority 45. Following such
2.6
WARNING
This boiler is equipped with
an automatic blocked vent
shutoff system. In the case
of an “Insufficient Airflow
Error” event, a licensed and
qualified service technician
shall follow the steps set out
at Section 5.3.1 Airflow.
Содержание SL 30-175
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