SVT Controller will not operate plant under Auto control following Clock replacement due to lack of re-commissioning.

[Product_Support]

Issue

SVT Controller will not operate plant under Auto control following Clock replacement

Environment

SVT 4201 Optimiser Controller 

SVT 4251 Optimiser Controller 

Cause

SVT Controller will not operate plant under Auto control following Clock replacement due to lack of re-commissioning.

Resolution

1. Re-commission SVT Controller using Test method.
   The absence of plant control may normally be confirmed by lack of illumination of Burner L E D (bottom left corner of SVT) 
2. Test method of re-commissioning may be undertaken as follows:
   1. Ensure SVT 4201 Analogue Clock override button is set to AUTO condition and Clock is in an ON period.
   2. Ensure SVT 4251 Digital Clock status is set to AUTO condition and Clock is in an ON period.
   3. Ensure SVT Manual Override Switch (lower left of SVT) is set to AUTO
   4. Note SVT Preheat Selector Switch (lower centre of SVT) setting (scaled 1,2,3,4,5,T)
   5. Turn Preheat Selector Switch fully clockwise from Preheat number setting to letter T
   6. Turn Manual Override Switch fully anti-clockwise from AUTO setting to O (Off) 
   7. Turn Manual Override Switch fully clockwise from O (Off) setting to + (ON)
   8. Burner L E D should illuminate and plant should start.
   9. Turn Manual Override Switch anti-clockwise from + (ON) setting to AUTO
   10. Burner L E D should remain illuminated and plant should continue to run.
   11. If plant continues to run then proceed to action L.  If plant remains OFF then return to action A.
   12. Turn Preheat Selector Switch anti-clockwise from T position to previously noted SVT Preheat Selector Switch setting.