Vulcan-Hart C24EA Series Service Manual page 54

C24EA SERIES ELECTRIC CONVECTION STEAMERS - ELECTRICAL OPERATION
Switch (2PAS),
Pressure . . . . . . . . . . . . . .
Thermostat (1TAS),
Condensate . . . . . . . . . . .
High-Limit (2TAS),
Steam Generator . . . . .
High-Limit (3TAS),
Heat Exchanger . . . . . .
Transformer (1T),
Main . . . . . . . . . . . . . . . . . .
Relay, Heat Exchanger
(K10) . . . . . . . . . . . . . . . . . .
Relay, Heat Exchanger
(K12) . . . . . . . . . . . . . . . . . .
Control Board . . . . . . . .
NOTE: The relay's below are mounted on the control board and are individually replaceable.
Relay (K1) . . . . . . . . . . . .
Relay (K2), Delime . . . .
Relay (K3), Drain
Relay . . . . . . . . . . . . . . . . .
Relay (K4), Delime . . . .
Relay (K5) . . . . . . . . . . . .
Relay (K6) . . . . . . . . . . . .
Relay (K7) . . . . . . . . . . . .
Relay (K8), Cavity . . . .
Relay (K9), Cavity . . . .
Relay (K11), High
Limit . . . . . . . . . . . . . . . . . .
F35453 Rev. A (0119)
Vacuum and fill pressure sensing for the steam generator. When generator is draining,
provides power to vacuum relief solenoid to prevent a vacuum from developing in the
steamer. When generator is initially heating and pressurizes above 4" W.C. the pressure
switch opens to remove power from vacuum relief solenoid to allow generator to reach
operating pressure.
Monitors temperature of water entering the facility drain system. Controls the drain
cooling solenoid during cooking operation and drain cycle (130°F close).
Protects steam generator heating elements from overtemperatures. Capillary tube device
(257°F cut-out; 246°F auto reset).
Protects heat exchanger elements from over-temperatures. Surface mount device (500°F
cut-out; auto reset 450°F).
Step down transformer from line voltage to 120VAC control circuit voltage.
Connects heat exchanger element (1) to power. On constantly whenever one or both
cooking compartment timers are set.
Connects heat exchanger element (2) to power. On constantly whenever both cooking
compartment timers are set.
Controls steam generator operation, draining and deliming functions. Provides a central
location for wire harness connections and power transfer thru board relays K1 thru K9
and K11 to the steamer controls. Houses 18 LED's for visual operation status and
troubleshooting.
Controlled by pressure switch (1PAS). K1 relay is energized when the pressure switch
N.O. contacts close.
Controlled by delime circuit. K2 relay is energized when delime switch is turned on
(momentary).
Controlled by drain time delay relay. K3 relay is powered when power switch is turned
off and drain time delay is energized for the drain cycle.
Controlled by delime circuit. K4 relay is energized when delime switch is turned on
(momentary).
Controlled by delime circuit. When delime valve is energized, the delime valve end switch
contacts close and K5 relay is energized.
Controlled by delime switch. K6 relay is energized when delime switch is turned to
CANCEL to stop a delime cycle.
Controlled by delime circuit. K7 relay is energized when delime time delay relay 1 is
energized during delime cycle.
Controlled by upper cooking compartment timer. When timer is set, K8 relay is energized
and K8- 5/3 contacts close to provide power to cavity condensate solenoid and heat
exchanger relay (K10). Heat exchanger element (1) energized.
Controlled by lower cooking compartment timer. When timer is set, relay is energized
and power is provided thru K8-1/5 N.C. contacts to cavity condensate solenoid and heat
exchanger relay (K11). Heat exchanger element (2) energized.
Controlled by high limit thermostat (2TAS). Relay is energized if high limit thermostat
opens. When high limit closes, relay remains energized thru K11-5/3 contacts until power
is removed from steamer.
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