iWorx® LCI3
502-050A, Effective: April 22, 2013
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© 2013 Taco Electronic Solutions, Inc.
• When connecting temperature inputs (Analog sensors) to the controller shielded cable is recommended. Recom-
mended wire includes 14-22 AWG stranded twisted shielded pair for all analog inputs with 18 AWG recommended.
Shields must be connected to an earth ground near the controller.
What Sensors are Required on the BLMC?
• A SENSOR IS REQUIRED ON THE BOILER SUPPLY INPUT (terminal PST; terminals 17&18) BOILER RETURN
INPUT (PRT terminal terminals 19&20). The Boiler Return Sensor is optional, only if the boilers need boiler protec-
tion, the sensor must be populated and the "Max Differential Setting" in the "System Settings" Structure must be
set to a value other than 0 F.
How Do I Zone with a BLMC?
Zoning can be accomplished as follows:
• With traditional zoning methods using pump relays or zone valves with end switches. Remember this requires a
dry contact from the zone panel or end switch wired into the Reset Demand input of the BLMC.
• A BZUx (Boiler Zoning Unit) or ZXU1 (Zone Mixing Unit) networked to a BLMC.
How do I wire zone valves to the BZUx outputs?
The BZUx outputs simply switch the 24 VAC common leg. So all you need to do is bring one side of the 24VAC to one
terminal of the zone valve, and return the other leg of the zone valve to an output terminal on the BZUx (for example:
terminal 31). The common terminal associated with that terminal of the BZUx goes back to the transformer common. In
this fashion, when the BZUx calls for heat, the common is switched and power is provided to power the zone valve
open. For wiring to BZUx outputs refer to the ‘iWorX Hydronic application and wiring guide’.
What types of zone valves are recommended?
Since the BZUx outputs are capable of handling up to 1 amp of current draw, we highly recommend a motorized zone
valve. We discourage the use of heat operated zone valves since these valves draw nearly 1 amp of current and tend
to generate significant heat when activated.
Notes:
