Service & Troubleshooting Guide #15-06-007
Verifying 4–20 Output
on Honeywell UDC 2500 modulation controllers
Following the completion of the burner purge cycle, burner control will be transferred from Fireye flame control system to Honeywell UDC 2500 modulation controller. At this point, the controller uses a 4–20 milliamp signal to communicate with the burner and modulation motor (via the mod motor resistor board).
This Service & Troubleshooting Guide from the CEI Service Dept describes how to check for and confirm the 4—20 mA signal from the Honeywell UDC modulation controller.