Lochinvar 500, 90 Temperature Control Sensors, Inlet Water Temperature Sensor, System Sensor

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5Electrical connections

Temperature Control Sensors

This is a two-stage temperature control (M9/F9) that controls the burner ignition and pump functions. This temperature controller can measure up to three different sensor inputs, depending upon how the unit is set up. They are as follows:

1.Inlet Water Temperature Sensor

2.Multi-Purpose Temperature Sensor

3.Outside Air Temperature Sensor

Inlet Water Temperature Sensor

This sensor measures the inlet water temperature coming into the unit.

The inlet water temperature sensor is placed into the inlet bulbwell on the boiler. This sensor is installed by the factory.

Multi-Purpose Temperature Sensor

Depending upon how your unit is set up, this sensor can be used as a system sensor in a boiler system or a tank sensor for water heater applications. Connect this sensor to the two blue wires in the upper left-hand corner of the control panel.

Outdoor Air Temperature Sensor

The outside air temperature sensor will only be used for boiler systems. The outside air sensor is optional. This sensor allows you to tie boiler operation to the outdoor air temperature. As outside temperatures drop, the control will increase the temperature setting of the boiler. As outdoor temperatures rise, the control will decrease the temperature to the selected set point of the boiler. You can set the control to shut the boiler off when a desired outdoor air temperature level is reached.

You must purchase the sensor from the appliance manufacturer. The sensor comes with a housing that helps protect the sensor from the elements. Mount the air sensor housing outdoors, under the eve of the roof. Make sure the housing is out of direct sunlight. This will ensure that the sensor will accurately read the true outdoor temperature. Connect the outdoor air temperature sensor to the terminal block on the outdoor air reset board. For more information on wiring the sensor, see Wiring of Remote Sensors, this page.

Installation of Remote Sensors

Make sure to insert the sensor all the way into the bulbwell, leaving no air pocket between the front surface of the sensor and the back of the bulbwell. Air pockets are thermally non-conductive and will cause sensors to read inaccurately.

System Sensor

The system sensor must be installed when piping the boiler in Primary - Secondary fashion when using the Pump Delay option.

Installation & Service Manual

Tank Sensor

Water heaters are provided with an extra temperature sensor that MUST be field installed. The sensor is shipped loose in the I & O packet. This remote mounted sensor will be the primary temperature sensor which will inform the appliance’s built-in thermostat control. For domestic water heating, the sensor MUST be installed into a bulbwell on the storage tank. This is required to maintain the desired temperature in the tank and reduce cycling of the heater.

In both applications be sure to insert the sensor all the way into the bulbwell, leaving no air pockets between the front surface of the sensor and the back of the bulbwell. Air pockets are thermally non-conductive and will cause sensors to read inaccurately.

Wiring of Remote Sensors

To wire remote sensors, follow the guidelines below. Take care to correctly wire sensors to the unit. Erratic temperature readings can be caused by poor wiring practices. Twist the wires between the unit and the remote sensor. Turn wires at least three or four turns per linear foot of wiring. This provides protection against some types of electrical interferences.

1.Do not route temperature sensor wiring with building power wiring.

2.Do not locate temperature sensor wiring next to control contactors.

3.Do not locate temperature sensor wiring near electric motors.

4.Do not locate temperature sensor wiring near welding equipment.

5.Make sure good mechanical connections are made to the sensor, any interconnecting wiring and the controller.

6.Do not mount sensor with leadwire end pointing up in an area where condensation can occur.

7.Use shielded wiring to connect the sensor to the control when the possibility of an electrically noisy environment exists. Shielded cable is recommended on all cable runs of more than 25 feet in length.

NOTICE

Ground the cable shield at the

connection to the boiler temperature

 

 

 

control only. Do not ground the

 

shielded cable at the sensor end.

To maintain temperature accuracy, sensor wires should be 18 AWG two conductor (18/2). Use shielded wire if required.

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Contents Models 90,000 500,000 Btu/hr Contents Please read before proceeding Checking equipmentCodes Ratings Copper-fin =B=R RatingCopper-fin Specifications Copper-fin How it works Gas connection pipeModels CWN270 Front View Model CWN399 Front View 422 Determine unit location Location of unitDetermine boiler location 3Combustion Air Direct from Outside6Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Venting Conventional Negative Draft Venting SystemVent Pipe Sizes Venting Vertical Vent Termination Clearances Less from Ridge From Parapet WallMasonry Chimney Installation Vent MaterialsSidewall Venting NumberAutomatic Vent Damper 7CB with Vent Damper and Vent Damper Terminal BlockGas connections Gas Supply Gas Pressure TestGas Connection Manifold PressureInstall Piping to Control Gas PipingGas Manifold Pressure Adjustment Procedure Clockwise to raise regulator gas pressure, counterclockwiseChecking Gas Supply Pressure 4Gas Supply PressureCombination Gas Valves Venting of Combination Gas ValvesTwo Stage Burner Control System Water Flow Switch if equipped Hydronic pipingRelief Valve Typical Heating Boiler Installations Low Water Cutoff if equippedMinimum Required Flow For Heating Boiler General Plumbing RulesSystem Temperature Rise Chart Piping of the Boiler SystemHeat Exchanger Pressure Drop Chart Circulator Pump SpecificationsWater Connections Heating Boilers Only Circulator Pump RequirementsPrimary/Secondary Boiler Piping Three Way Valves Boiler Flow RatesPrimary / Secondary Piping 4Primary / Secondary Piping of a Single BoilerNot to Exceed 4 Pipe DIA or MAX. of 12 Apart 8Multiple Boilers Zoned with Circulators Terminal Strip Wiring Boiler Operating Temperature ControlPower Venter Connection to Terminal Strip Electrical connectionsTemperature Adjustment Pump Wiring for a Heating BoilerOperating Temperature Control Locating Temperature Control Temperature Control SettingsMaximum SET Point Determination Maximum Set Point DeterminationTemperature Control Sensors Inlet Water Temperature SensorMulti-Purpose Temperature Sensor Outdoor Air Temperature SensorOutdoor Air Reset Option Installation of a Remote Sensor Boiler ApplicationInstallation of a Tank Sensor Water Heater Application Additional Temperature Controls Blocked Vent and Flame Roll-Out / Flame Interlock Switch Manual Reset High Water Temperature Limit ControlPre-start Checklist Start-upInitial Start-up Lighting Instructions 1Gas Valve 90,000 270,000 Btu/hr ModelsSafety Shutoff Test For Standing Pilot Ignition System To Turn OFF GAS to ApplianceOperating Instructions Safety Shutoff Test for Spark Ignition Pilot System Intermittent Pilot Spark Ignition System F9/M9Freeze Protection To Turn Off Gas to ApplianceWater Treatment Freeze Protection for a Heating Boiler System if requiredRequired Temperature Rise Required Temperature RiseDomestic water heaters Domestic Water Heaters 90,000 500,000 Btu/hr ModelsWater Chemistry Softened Water SystemsPump Operation 1Single water heatersingle tank 2Single water heatermultiple tank 3Multiple water heatersingle tank Remote Sensor Installation Thermostat SettingsMinimum Pump Performance Heat Exchanger5Danger Warning Water Flow Switch if equipped Pressure Only Relief ValveThermal Expansion Cathodic ProtectionMaintenance and annual startup Service technicianOwner maintenance See the User’s Information Manual for instructionsMaintenance Check Expansion Tank Check Relief ValveCheck All Wiring Check Control SettingsCombustion Air Adjustment Perform Start-up and ChecksInspect and Clean Burner Heat Exchanger / Burner AccessInspection and Cleaning Procedure Pilot Flame Adjustment Procedure Clear AreaInspection of Heat Exchanger Waterways Water Circulating PumpReview with owner Gas Train and ControlsTroubleshooting Pilot or replace Diagrams Schematic Diagram F1 UnitWiring Diagram F1 Unit 90,000 270,000 Btu/hr ModelsSchematic Diagram F9 Unit Wiring Diagram F9 Unit315,000 399,999 Btu/hr Models Diagrams Diagrams Page Revision a ECO #C06290 initial release CFA-I-S Rev a 09/10
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