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| Installation & Operation Manual |
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7 Field wiring |
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System supply sensor | Wiring of the cascade |
1.By installing the system supply sensor into the supply of the primary loop, the temperature of the system supply can be controlled. The SMART TOUCH control automatically detects the presence of this sensor, and controls the boiler firing rate to maintain the system supply temperature to the set point.
NOTICE | DO NOT INSTALL THE SYSTEM | |
SUPPLY SENSOR INTO THE SYSTEM | ||
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| RETURN. |
2.Connect these terminals to the system supply sensor (FIG.
NOTICE | A system supply sensor (factory supplied) | |
MUST BE installed for proper boiler | ||
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| operation. |
Boiler management system
1.An external control may be connected to control either the firing rate or the set point of the boiler. Connect the 0 - 10 VDC terminals to the 0 - 10 VDC output of the external control. The SMART TOUCH control can be enabled using the Enable output (see page 39) or using the voltage applied to the 0 - 10 VDC input. Reference the SYNC Service Manual for more details.
2.Make sure the ground terminal is connected to the ground output terminal of the external control, and the 0 - 10 VDC terminal is connected to the 0 - 10 VDC terminal of the external control.
Runtime contacts
The SMART TOUCH control closes a set of dry contacts whenever the burner is running. This is typically used by Building Management Systems to verify that the boiler is responding to a call for heat.
Alarm contacts
The SMART TOUCH control closes another set of contacts whenever the boiler is locked out or the power is turned off. This can be used to turn on an alarm, or signal a Building Management System that the boiler is down. Note that these contacts will close momentarily at the end of each call for heat or at least every 24 hours.
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When wiring the boilers for Cascade operation, select one boiler as the Leader boiler. The remaining boilers will be designated as Members. See page 48 “Configuration of the Cascade” for a detailed explanation of this procedure.
Connect the system supply sensor and outdoor air sensor (if used) to the Leader boiler. For the Cascade system to work properly the system supply sensor must be installed.
NOTICE | A system supply sensor (factory supplied) | |
MUST BE installed for proper boiler | ||
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| operation. |
The location of the system supply sensor should be downstream of the boiler connections in the main system loop (FIG.’s
If outdoor air reset is desired, the outdoor air sensor should be wired to the Low Voltage Connection Board at the terminals marked for the outdoor air sensor on the Leader boiler (FIG.
If a Thermostat or Zone Control enable output is available, it should be wired to the Low Voltage Connection Board on the Leader boiler at the terminals marked Enable (FIG.
Communication between the Leader boiler and the Member boilers is accomplished by using shielded,