Crestron electronic 3.5, 2 Auxiliary switch 1, System supply sensor, Boiler management system

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7 Field wiring (continued)

Auxiliary switch 1 & 2

Additional field supplied limit controls may be connected to the auxiliary switch inputs. If additional limit controls fail or open, it will result in a manual reset lockout.

System supply sensor

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

 

 

RETURN.

2.For system supply sensor wiring information reference (FIG. 7-3).

Unless a firing rate is being provided by NOTICE a BMS system, a system supply sensor (factory supplied) MUST BE installed with Primary/Secondary piping systems

for proper boiler 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 38) or using the voltage applied to the 0 - 10 VDC input. Reference the Crest Service Manual for more details.

2.Make sure terminal #34 on the Low Voltage Connection Board is connected to the (-) or COM output terminal of the external control, and 0 - 10 VDC terminal #33 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.

System return sensor

1.Install the system return sensor into the return of the primary loop.

2.Connect the terminals to the system return sensor as shown in FIG. 7-3.

Installation & Operation Manual

Wiring of the cascade

When wiring the boilers for Cascade operation, select one boiler as the Leader boiler. The remaining boilers will be designated as Members. See page 45 “Configuration of the Cascade” for a detailed explanation of this procedure.

Connect the system supply sensor, system return sensor and outdoor air sensor (if used) to the Leader boiler.

NOTICE

Unless a firing rate is being provided by a

BMS system, a system supply sensor (factory

 

 

supplied) MUST BE installed with Primary/

 

Secondary piping systems for proper boiler

 

operation.

The location of the system supply sensor should be downstream of the boiler connections in the main system loop (FIG.’s 5-5 and 5-6). The system supply sensor should be wired to the Low Voltage Connection Board at the terminals marked for the system supply sensor (see FIG. 7-3). The Leader control will use the water temperature at the system supply sensor to control the operation of the Cascade.

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. 7-3). If the outdoor air sensor is connected, the Leader control will calculate the water temperature set point based on the programmed reset curve parameters. If the outdoor air sensor is not connected, the Leader control will maintain the fixed water temperature set point that is programmed into the control.

If a Thermostat enable output is available, it should be wired to the Low Voltage Connection Board on the Leader boiler at the terminals marked Enable (FIG. 7-3). If the boilers are to run continuously, connect a jumper wire between the 7 and 8 terminals at the Enable input. This will initiate a call for heat on the Cascade. If the SMART TOUCH control is being controlled by a Boiler Management System (BMS), a call for heat may be initiated by the voltage applied to the BMS 0 - 10 VDC input instead.

Communication between the Leader boiler and the Member boilers is accomplished by using shielded, 2-wire twisted pair communication cable. Connect one of the twisted pair wires to Cascade terminal A on each of the Low Voltage Connection boards, and the other wire of the twisted pair to Cascade terminal B on each of the Low Voltage Connection Boards. Connect the shield wires to one of the Cascade shield ground terminals on the Low Voltage Connection Boards (FIG. 7-3). If more than two boilers are on the Cascade, daisy chain the wiring from the Cascade terminals on the second boiler to the Cascade terminals on the third boiler, then from the third to the forth, and so on. The connections between boilers can be made in any order, regardless of the addresses of the boilers. Try to keep each cable as short as possible.

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Contents Save this manual for future reference Contents Please read before proceeding When servicing boilerBlowers Crest How it worksCrest How it works Models 1.5 2.0 2.5 3.0 Crest Ahri Rating RatingsDetermine boiler location Installation must comply withBefore locating the boiler, check Provide clearancesFlooring and foundation Provide air openings to roomVent and air piping Prevent combustion air contaminationProducts to avoid When using an existing vent system to install a new boilerAreas likely to have contaminants When removing a boiler from existing common vent system Remove boiler from wood pallet 7Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Direct venting General ventingOptional room air Air inlet pipe materials Install vent and combustion air pipingAir intake/vent connections Approved Stainless Steel Vent Manufacturers Make ModelRemoving from existing vent Common venting Vent/air termination vertical Vertical direct ventingDetermine location Prepare roof penetrations4Alternate Vertical Terminations with Multiple Boilers Multiple vent/air terminationsVent/air termination sidewall Sidewall direct venting2Clearance to Doors and Windows Prepare wall penetrations4Multiple Vent Terminations must also comply with Figure Room airHydronic piping Model Circulator sizing20F 40F 60F Near boiler piping components System Multiple Boilers Common Header Primary / Secondary Flow For all equipment and detailing required by local codes Hydronic piping Gas connections Connecting gas supply pipingModel Gas Inlet Size Propane Gas Natural gasCheck inlet gas supply GAS Piping Size ChartGas Pressure Gas valve replacementInstallation must comply with Field wiringLine voltage connections Outdoor temperature sensor EnableLouver proving switch Low voltage connectionsAlarm contacts Auxiliary switch 1Wiring of the cascade System supply sensorField WiringCondensate drain Condensate disposalStart-up Freeze protection when usedCheck/control water chemistry Fill and test water systemCheck thermostat circuits Check for gas leaksInspect condensate system Inspect/check condensate lines and fittingsStart the boiler Final checks before starting the boilerIf boiler does not start correctly Check system and boilerFor Your Safety Read Before Operating Gas Natural Gas Propane Valve Set space heating operationConfiguration of the cascade Verify HWG circulator mode Set HWG target temperatureSet clock General Operating informationProtection features Outdoor reset operation, if used Boiler temperature regulationCascade Sequence of operation Home Screen Crest control module2Main Menu Screen Service technician Maintenance Maintenance and annual startupOwner maintenance See the Crest User’s Information Manual for InstructionsMaintenance Check water system Flue vent system and air pipingCheck expansion tank Check boiler relief valveCheck all boiler wiring Check ignition ground wiringCheck control settings Check flame signalReview with owner Cleaning boiler heat exchangerHandling ceramic fiber materials Niosh stated First AidIntegrated Control Diagrams2Wiring Diagram
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