Field Testing Of High Limit Switches - Viessmann Vitocrossal 300 CU3A 26 Installation Instructions Manual

Vitocrossal 300 CU3A 26 to 199 Installation
Important Regulatory and Installation Requirements
CSD-1 Field Testing of High Limit Switches for Vitocrossal 300 CU3A boilers – where required by law.
VIESSMANN IS NOT RESPONSIBLE FOR ANY DAMAGES THAT THE FOLLOWING TEST PROCEDURE MAY RESULT
IN BY OVERHEATING THE SYSTEM.
The fixed high limit, when tripped, produces a fault that will require manual reset of the boiler control.
Fixed High Limit fault simulation:
- Run the boiler to high fire via relays test.
- Throttle the boiler valve to a point where the burner will run with as little flow as possible.
- When the burner shuts down on the electronic limit, close the ball valve to stop the flow.
- The boiler temperature should continue a steady increase to trip the fixed high limit.
- Once the fixed high limit is tripped, slowly open the boiler valve to safely cool the boiler down.
General Information
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