Lochinvar 45000, 260000 Maximum SET Point Determination, Maximum Set Point Determination

Installation & Service Manual

5Electrical connections

Maximum Set Point Determination

The maximum set point for the control is factory set. Boilers can be set to 240°F max.

These maximum set points are established by cutting the OJ1 and OJ2 jumpers located on the right side of the temperature controller. The maximum set point is determined as shown below in Table 5C.

TABLE - 5C

MAXIMUM SET POINT DETERMINATION

OJ1	OJ2	MAX.
		SET POINT
Connected	Connected	240°F
Cut	Connected	190°F
Connected	Cut	200°F
Cut	Cut	160°F

	Anytime that OJ1 is the only jumper cut, a
NOTICE
	new overlay is required under the Set
	Point knob on the temperature controller
	because the scale has changed to a
	maximum of 190°F.

Anytime the OJ2 jumper is cut (with or without OJ1), a new overlay is required under the Set Point knob on the temperature controller because the scale has changed to a maximum of 200°F.

Set Point

The Set Point knob specifies the target inlet water temperature in degrees, Fahrenheit. After the water temperature reaches the set point, the temperature control shuts off the burners.

Differential

The Differential specifies the number of degrees below the set point that the control will allow the water temperature to drop before it brings the unit back on again.

High-Fire Offset

The temperature control operates a two-stage firing system. The two stages are High-Fire and Low-Fire. High-Fire operates all burners at full rate while Low-Fire operates the burners at approximately one-half rate.

The High-Fire Offset knob specifies the number of degrees below set point that the High-Fire stage shuts down. At that point, the unit will continue to operate at the Low-Fire stage until the set point is reached.

The High-Fire Offset knob has settings between 0°F and 20°F. If set at 0°F, the High-Fire Offset is disabled and the unit will operate the High-Fire stage until the set point is reached and the temperature control shuts the unit off.

If the High Fire Offset knob is set to 0 or 1, the delay will be 10 seconds; if set to 2 or above the delay will be 120 seconds.

Boiler Application

Standard boiler units are equipped with one inlet water temperature sensor. A system sensor is also provided for use as a remote system sensor. Boilers with the outdoor air reset option also have an outside air temperature sensor.

Temperature Control Sensors

This is a two-stage temperature control 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.System 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 in new units.

System 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 SYS/TANK contacts on the control board.

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