Cleaver-Brooks CBW - F. Modulating Motor Does Not Operate

CHAPTER6
(7) Improper air.fuel ratio (lean fue ).
(a) Slipping linkage.
(b) Damper stuck open.
(c) Fluctuating fuel supply.
(i) Temporary obstruction in fuel
line.
(ii) Temporary drop in gas pressure.
(iii) Orifice gate valve accidentally
opened (heavy oil).
(8) Interlock device inoperative or defec-
tive.
F. MODULATING MOTOR
DOES NOT OPERATE
(1) Manual-automatic switch in wrong
position.
(2) Linkage loose
or jammed.
750-150
TROUBLE SHOOTING
(3) Motor does not drive to open or close
during pre-purge or close on burner
shut·
down.
(a) Motor defective.
(b) Loose electrical connection.
(c) Damper motor transformer defective.
(4) Motor does not operate on demand.
(a)
Manual:-automatic switch in wrong
position.
(b) Modulating control improperly set or
inoperative.
(c) Motor defective.
(d) Loose electrical connection.
(e) Damper motor transformer defective.
CHAPTER 6..S