TurboChef SOTA NGO, Service Manual

Page: 40 / 85

OVEN SY
STEMS
19
Convection System
The convection system is designed to rapidly heat,
clean, and recirculate air into the cook cavity.
This section contains information about the
following components:
- Blower motor (bottom)
- Blower motor (top)
- Blower motor speed controller (BMSC)
- Heater elements
- Jetplate (bottom)
- Jetplate (top)
- Stirrer motor and assembly
For information on accessing and removing parts,
see the Appendix.
Blower Motor (Bottom)
The bottom blower motor is a brushless AC-switch
reluctance type and spins clockwise. Its top speed
is 7100 RPM at 1 HP, and it is controlled by a
proprietary controller.
The bottom blower motor can be tested in Test
Mode (see page 13).
Blower Motor (Top)
The top blower motor is a brushless AC-switch
reluctance type and spins counterclockwise. Its top
speed is 7100 RPM at 1 HP, and it is controlled by
a proprietary controller.
The top blower motor can be tested in Test Mode
(see page 13).
Blower Motor Speed Controller (BMSC)
The motor controller is proprietary and will only
operate the motors described above. It is controlled
via 0-10 VDC speed command from the I/O
control board and can be tested in Test Mode by
testing the blower motors (see page 13). For
additional troubleshooting, see page 33.
Heater Elements
The main convection heaters are sheathed-style
and rated at 3000 watts at 208 VAC, with a
resistance of 14.4 Ohms. The convection heaters
are controlled by the K4/K5 solid state relay, and
can be tested in Test Mode (see page 13).
Jetplate (Bottom)
The bottom jetplate channels air generated from
the bottom blower motor into the cook cavity.
Jetplate (Top)
The top jetplate channels air generated from the
top blower motor into the cook cavity. Before the
air passes through the jetplate nozzles, it is mixed
by a stirrer.
CAUTION: The top jetplate is ceramic. Be
careful when removing or reinstalling it.
Stirrer Motor and Assembly
The stirrer is responsible for evenly distributing
hot air and microwave that enters the cook cavity
from the top. The stirrer is driven by a motor that
remains on during a cook cycle or when the oven
is in Test Mode. The stirrer motor turns off when
the cook cavity temperature recedes below 150°F
(66°C).
The stirrer motor can be tested in Test Mode (see
page 13).
Troubleshooting
The following faults may occur in relation to the
convection system:
-F1: Blower (see page 33)
-F2: Low Temp (see page 34)
-F6: EC Temp (see page 37)
-F7: Thermo (see page 37)
-F8: Heat Low (see page 38)
The following cooking performance issues may
occur in relation to the convection system:
-Food not cooking properly (see page 41)