Testing For Control Voltage To The K8 Relay (Gen 1); Testing Relay 14 (Pre-Heat) Operation (Gen 2); Testing For A K9 Relay That Is Stuck Open; Testing For A K1 Ssr That Is Stuck Open - TurboChef Residential Single and Double Wall Oven Service Manual

Testing for Control Voltage to the K8 Relay (Gen 1)

DANGER: A high-voltage capacitor is located
near this relay. Contact with the high-voltage
capacitor could result in serious injury or death.
1. Turn the CookWheel to Bake to begin the
preheat cycle.
2. Apply the probes of the voltmeter to P7 – 8 and
P8 – 9 (on the control board). Th e voltage
reading should be 24 VDC.
- If 24 VDC is present, the relay is receiving
voltage.
- If either/both of the relays fail to receive
voltage, replace the control board and test
the oven. If both relays are receiving 24
VAC, pull the oven out of the cabinet to
test the K9, K1, and K8 relays, as well
as the heating elements.

Testing Relay 14 (Pre-Heat) Operation (Gen 2)

1. Turn the CookWheel to Bake to begin the
preheat cycle.
2. Apply the amprobe to the wire on terminal
RBJ11 and confi rm a measurement of approxi-
mately 9 amps is present. If 0 amps is present,
ensure the pre-heat element is not faulty by
checking the L1 voltage at terminal RBJ-10 to
ground and RBJ-11 to ground (of the relay
board). If voltage is present, continue.
NOTE: L1 voltage enters the relay board from the
high limit switch at terminal RBJ-10 and leaves
through RBJ-11.

Testing for a K9 Relay that is Stuck Open

1. Disconnect the single blue L2 wire and the three
blue L2 wires from the K9 relay.
2. Turn the CookWheel to Bake to activate the K9
relay; it should make an audible click if
functional.
NOTE: Th e K9 relay uses 120 VAC to activate the
coil.
3. Apply the probes of the multi-meter to the
common and N.O. terminals of the K9 relay
that are now exposed. Th ey should register
continuity with an ohms test. If they do not,
verify the relay is receiving voltage from the blue
wires still attached to the relay in the upper-left
corner.
4. If voltage is present, replace the relay and test
the oven. If no voltage is present, investigate for
broken wires.
5. If the K9 relay is functioning normally, test if
both the K1 and K8 relays are stuck open.

Testing for a K1 SSR that is Stuck Open

DANGER: A high-voltage capacitor is located
near this relay. Contact with the high-voltage
capacitor could result in serious injury or death.
Before servicing:
a) Remove power from the oven.
b) Discharge the high-voltage capacitors.
c) Disconnect the primary voltage wiring of the
high-voltage transformers.
1. After completing safety instructions above,
reconnect power to the oven and turn the
CookWheel to Bake.
2. Th e solid state relay is unable to be checked with
an ohm test for continuity. Test for voltage
through the switch by energizing the relay and
leaving the brown wires connected, but pulled
back enough to get a meter probe on the
terminal.
CAUTION: DO NOT touch the meter leads
together; this will cause the relay to short.
3. Set the meter to AC volts. A reading of 0
indicates a closed switch, and a reading of 208/
240 indicates an open switch.
4. If both relays function normally, ohm out the
heating elements and inspect the element's
terminals.

Heating System, Lower Oven

Th e lower oven heating elements require 208-240
VAC to operate.
NOTE: Th e elements are voltage specifi c and cannot
operate properly without the correct voltage applied.
Confi rm incoming voltage matches the oven's
specifi cations (listed on the serial plate behind the
oven door).
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