Merrychef 402s - Manual (Page 27)

402s Ovens Pt. No. 32Z3522 Issue 6
27
PRINCIPAL COMPONENTS: Hot Air Motor & Controller 1
Convection and Fan Speed Control
The convection heat is provided by 5 elements located in the hot box at the rear of the oven
cavity. The hot air from the hot box passes over catalytic converters and is circulated into the
bottom and top of the cavity through the impinger plates. It returns through the removable grease
filter at the back of the cavity and into the fan.
Convection motor
The convection motor Is a 3-phase AC motor having a maximum speed of 7200 rpm controlled by
a motor speed controller.
The windings are thermally protected and in the event of a thermal fault a trip will operate and
shut down the motor speed controller.
Step Motor/ controller fault finding
1 208V/240V, 60Hz Electrical supply into motor controller
2 Three phase connections to motor
3 Speed Controller connections to logic board
4 Motor thermal cut-out (short circuit)
5 Motor rotates freely/ not seized
6 Motor winding resistances:
Blue-Black 3 Ohms—4 Ohms
Black-Brown 3 Ohms—4 Ohms
Brown-Blue 3 Ohms—4 Ohms
Black or Brown or Blue to Earth (Open circuit)
8x 31Z4016
M5 Flange nut
No. Description Part No.
20 Heater Element 208V 650W 68Ω DV0328
20 Heater Element 240V 650W 88Ω DV0337
20A Heater Element Collar DV0058
23 Convection ( Hot Air ) Motor Assembly SA208
Gasket Set SA332