Part 21 Description - 5100 Series

When the system receives a heat call from one of the zones in the application, the primary loop pump (circulator) is energized. The discharge water sensor monitors the temperature of the water at the outlet of the exchanger. If the discharge water temperature (as set in L000 and L001) is not being reached, the core blower is energized and circulates air through the brick core. This heated air heats the water in the exchanger to maintain the desired temperature.

The core blower speed is determined by the amount of voltage sent to the core blower from the base I/O relay board. As the fan speed requirements increase, voltage to the core blower increases. Refer to Location 120 (L120) for core blower speed. Check voltage AC from the L2 terminal to the blower terminal on the base I/O relay board and compare this reading to the Blower/Damper Activation Chart.

The core blower motor should be permanently lubricated and should not be oiled.

Vibration of the blower can be caused by failed bearings, a build up of dirt and debris on the blower wheel, loose mounting, or broken mounting system. If there is a noise issue, check the bearings, clean the blower wheel, and verify that the blower is mounted properly.

Operation (opening) of the thermal limit within the motor can be caused by a failure of the triac output of the base I/O relay board. If the motor is very hot, displays loud buzz, and does not turn or turns slowly, operate the motor from a remote power source to test or see 5100 - Core Blower Not Operating to troubleshoot.

All motor windings must have at least 20 meg ohms of resistance from each of the leads to ground. The capacitor used, resistance across the power lead wires, and resistance across the capacitor wires will vary depending on which motor is installed. Use the table below to determine which capacitor should be used for the application and to test resistance: