9-2. Limit Conditions

A limit condition indicates that the system has encountered an open thermocouple or is outside the range of its optimum operating conditions or parameters. Should a limit condition occur during operation, the yellow Limit LED will flash to indicate a problem. If the active screen on the LCD display is Run Status or Parameters, a message describing the particular limit condition will appear on the display. If the active screen is Program, press the

Run Status

button to display the limit condition.

In a limit condition, the power source will continue to deliver output power and protect itself from damage by reducing the output power. This situation allows the operator time to determine the best action to correct the problem as described by the limit message on the LCD display.

If a limit condition occurs, there are two selectable options:

SAcknowledge the limit and continue operation.

STerminate operation to correct the problem causing the limit.

Pressing the Decrease

button will acknowledge the limit and continue operation with the existing set up. In the acknowledge state, the yellow

Limit LED will stop flashing and remain on continuously. The LCD display will revert to an active screen once the Program

button, Run Status

button, or Parameters

kW

button is pressed.

 

V A

 

 

Hz

 

 

If a new limit condition should occur after the first is acknowledged, the yellow Limit LED will start flashing to indicate a new problem. To display the limit

condition, press the Run Status

button and the LCD display will show a message describing the new and previous limit messages.

To obtain additional information regarding the limit condition and suggested solutions to resolve the limit, press the Increase

LCD display will indicate possible solutions based on the type of limit condition.

button, and the

If the operator determines that the best course of action is to terminate operation and make suggested changes to the setup to eliminate the limit condi-

tion, press the Stop button. After changes are made to the setup, press the Run button to restart the process.

9-3. Limit Condition Codes

Limit Condition

Additional Information

 

 

L01: Thermocouple #1 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L02: Themocouple #2 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L03: Thermocouple #3 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L04: Thermocouple #4 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L05: Thermocouple #5 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L06: Thermocouple #6 Open

Check for open temperature sensor and repair

 

Change to back-up temperature sensor

 

 

L07: Output Voltage Limit

Tighten blanket against pipe surface

 

 

L08: Output Voltage Limit

Increase number of turns

 

Increase coil space

 

Shorten extension cable

 

Increase insulation width

 

 

L09: Output Current Limit

Tighten blanket against pipe surface

 

 

L10: Output Current Limit

Increase number of turns

 

Decrease coil space

 

Tighten cable on insulation

 

 

OM-222 166 Page 42

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Miller Electric ProHeat 35 Limit Conditions, Limit Condition Codes, Run Status, Limit Condition Additional Information