IBC SL 20-160 G3, Installation And Operating Instructions Manual

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INSTALLATION AND OPERATION INSTRUCTIONS
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SL 10-85 G3, SL 14-115 G3, SL 20-160 G3, SL 30-199 G3 MODULATING GAS BOILERS
1.8.5 Other Wiring
Other optional low voltage connections to the control board include:
• Two auxiliary interlocks - for external safety devices as may be required by some
jurisdictions, such as a low water cut-off or a low gas pressure cut-out (for off-grid
propane).
• Contacts for indoor and outdoor temperature sensors associated with reset heating. A
10K ohm thermister for outdoor reset sensing is supplied with the boiler for improved
comfort and combustion efficiency.
• One pair for a DHW tank sensor. Connect to “DHW S” (not the respective Therm.
1,2,3,4 location), and the boiler automatically detects and calls a smart DHW routine.
• One pair of contacts for remote secondary loop temperature control.
• One pair (marked BoilerNet) for network connection – this is used for connecting
multiple SL and/or VFC modulating units for autonomous staging.
• The bottom pair of contacts receives a 0-10VDC (default) or 4-20 mA signal from an
external boiler controller for direct throttle control. The boiler’s own sensors act as high
limits only. The user must enter maximum and minimum boiler supply temperatures.
NOTE: Sensors connected to any sensor input contacts must be of the NTC Thermister
type with a resistance of 10,000 ohms at 25°C and β = 3892. We do not recommend using
3rd party supplied sensors. Compatible water temperature sensors and outdoor sensors
can be supplied by your IBC distributor.
1.8.6 Thermostat Heat Anticipator
IBC “Therm.” contacts draw no power, so an anticipator setting for the thermostat is not
applicable with the SL modulating series boilers. In the case of a single temperature / heat
load where zone valves are used to manage individual thermostatically controlled zones,
each room thermostat’s heat anticipator should be adjusted to the current draw of its
associated zone valve.