IBC SL 35-199 Operating Instructions Manual page 33

NOTE
The IBC boiler (like any
modern appliance that
contains electronic
equipment), must have a
"clean" power supply, and is
susceptible to power surges
and spikes, lightning strikes
and other forms of severe
electrical "noise". Power
conditioning equipment
(surge protectors, APC or
UPS devices) may be required
in areas where power quality
is suspect.
DANGER
Do not connect thermistor
sensors to "Therm" terminals.
An overheating hazard can
result in serious personal
injury and/or property
damage. See Controller
Manual section 2.1.1 for
detailed instructions.
NOTE
The IBC Touch-Screen
controller has the ability
to connect to most power
stealing thermostats. See the
Wiring Diagram for details.
INSTALLATION
SL 35-199, SL 45-260 MODULATING GAS BOILERS
1.8.2 Power Quality and Electrical Protection
In areas of unreliable power, appropriate surge protectors and or power
conditioning equipment should be installed in powers supply wiring circuits.
1.8.3 Zone Valve Hook-up
If zone valves rather than pumps are used to manage multiple heating loads, then
24VAC for the zone valves should be provided to the power contacts on the Pump/
Zone Valve Terminal Block. Disconnect the 120 Vac leads connected to PV-L/PV-N
and cap off. Use a separate transformer – the 40VA unit inside the wiring box is for
internal systems only. The individual load/zone valves are then to be wired to their
associated contacts on the secondary pump/zone valve connector. Do not confuse
such "load/zone valves" with similar valves used to segregate a single load type
(e.g. those used on a zoned radiant floor) – see next section.
1.8.4 Thermostat / Sensor Wiring
Dry contacts for thermostats for each of 4 loads are provided as marked on the
lower connector strip (e.g. "Therm 1"). Gang lines from a multiple-zoned load
(e.g. off the end-switches for each radiant floor zone) to present a common
thermostat signal to the controller. Ensure there are no disturbing influences on
the call-for-heat lines - e.g. no coils to switch an air handler motor. Most power
stealing thermostats can be connected directly to the Therm terminals. See
Controller Manual section 2.1.1 for more detailed instructions.
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). A floor-protecting aquastat can use one of these, to
cause a full boiler shutdown in the case of excess floor temperature.
•
Contacts for indoor and outdoor temperatures sensors associated with Reset
Heating. A 10K ohm thermister for outdoor reset sensing is supplied with the
boiler, to encourage use of this temperature compensating space heating
technique 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 will automatically notice and go to 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.
See separate Technical Memo for guidance.
•
The bottom pair of contacts, to receive 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. User must enter maximum and minimum boiler
supply temperatures.
NOTE: Sensors connected to any sensor input contacts must be of 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.
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