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NORA Oilheat Technicians Manual

Thermostat R8184G Protectorelay® Control Junction Box R8184G or the White Rogers 668. They both feature intermittent duty ignition and operate as follows: If all components are functioning properly, the control is in stand-by mode until: • Power is applied through the limit control to the black wire, AND a call for heat from the thermostat completes the circuit between T and T. Then, assuming that the cad cell does NOT sense light… • The control is energized and the orange wire is powered. • The igniter generates ignition through the electrodes and the motor turns the fuel unit and burner fan. If there is an oil valve installed, it opens based on its delay timing. • Flame is established and the cad cell resistance decreases to fewer than 1600 ohms, de-energizing the safety switch heater and preventing the unit from shutting off on safety. • As long as the cad cell senses flame, the oilburner continues to run until either the thermostat or limit control is satisfied. Safety check Line Voltage Thermostat To check the safety: 1. Turn off the power at the service switch. 2. Install a 1,000 ohm resistor across the F-F terminals to reduce resistance and simulate flame. It is OK to leave the cad cell leads hooked up. 3. Turn on the service switch and make sure that both the line and low voltage circuits are complete. 4. The control should NOT energize, because the resistor connected to the F-F terminals simulates a fire in the chamber. If it does energize, replace the control. If it does not … 1. Turn off the service switch and remove the resistor. 2. Disconnect one lead from the F-F terminals. 3. Turn on the electrical switch. The control should energize and the burner should lock out based on safety switch timing (15 – 45 seconds.) If the control Chapter 11 Primary Controls Figure 11-6: Cad cell primary control Chapter 11—Primary Controls 11-9 Power Supply, Provide Disconnect Means and Overload Protection as Required To Use R8184 with Line Voltage Controller, Jumper T-T Terminals and Connect Line Voltage Thermostat in Series with Limit Controller. Cad Cell Black Orange White


NORA Oilheat Technicians Manual
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