Honeywell Rectification flame amplifier R7847A1074/U

The Honeywell R7847A1074/U is a solid-state, removable flame amplifier that operates on the principle of flame rectification. It is designed for use with Honeywell 7800 series relay modules, responding to input signals from a flame detector to indicate the presence of a flame. This dynamic self-checking amplifier measures flame signal intensity in the range of 0 to 5 V. It has dimensions of 91 mm width, 85 mm height, and 23 mm thickness, and weighs 70 g. The operating ambient temperature range is -40 to 60 °C. It connects to the relay module via an edge connector and is configured for its own orientation.

Parts of this type are selected by ensuring compatibility with the specific relay module series and the flame detection method. The amplifier must match the relay module's connector type and orientation. Before ordering, verify the dimensions and mounting form to fit the existing enclosure. The flame signal intensity range and ambient temperature limits should also be considered for the application.

When amplifiers of this kind fail, the burner may shut down or fail to start, often due to loss of flame signal detection. Symptoms include intermittent flame loss, false flame indications, or a complete lack of response to the flame detector. Check the amplifier's connections, the flame detector's condition, and the signal voltage to diagnose the issue.