DMW-22-TDL SERVICE MANUAL
Confidential and proprietary information of Meister Cook, LLC. Not to be reproduced or used in any manner other than
with the express written permission of Meister Cook, LLC.
10
|
P a g e
Under normal operation of the heater control circuit, AC line voltage crosses 0 Volts at a
frequency of 60Hz.
The power supply contains a circuit that monitors zero crossings.
If 16 half-cycles are not detected, the system will flag this condition and generate the error
code.
This fault is generally caused by a faulty power supply.
NOTE: this error code will
ALWAYS
occur at power down, as the heater control circuit ceases
to function. This is not an error and can be expected as normal.
FLT! 2222 – startup warming failure detected
Under normal preheating of the system, the measured temperature at the thermocouple
should rise a minimum of 16F over a 5 minute period.
This timer expires after the temperature reaches 120F.
This fault code is generated if the temperature measurement system does not detect a
minimum temperature rise of 8F over a 5 minute period.
NOTE:
with Firmware v1.49, this timer has been extended to a 16F temperature rise over a
10 minute period.
This fault code is intended to indicate a failed heater, as well as prevent the heater from
overheating in the event of a fault in the movement of air and/or temperature control circuit.
However, certain installation conditions could potentially trigger a false flag:
Abnormally cold unit
Pans not installed during preheat
Effects of cool air from HVAC system
Effects of heat from another piece of equipment installed too close to the DMW
A false flag can be determined by performing the following steps:
Turn off the system and turn it back on after 10 seconds.
If the temperature is below 120F, the internal timer will reset. Monitor the system
temperatures to ensure that the appropriate temperature rise is achieved.
After clearing the fault detection parameters, ensure that the system reaches the
appropriate setpoint temperatures and is able to maintain temperature.
If a false flag continues to occur on systems running on Firmware v1.46, it is recommended to
replace the UI Board with one that is running on Firmware v1.49.
FLT! 3333 – over-temperature detected
The system has a maximum temperature setpoint of 250F.
To prevent system damage, this fault code is triggered if a temperature equal to or greater
than 285F is reached.
A false high temperature will also be reached if there is an open thermocouple circuit.
This is a preventive scheme to not allow the system to heat if a thermocouple circuit is
broken.
