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Error code reference

Continental Washer Error Code A-b

Input Phase Loss

Continental codesContinental washer codes

Input Phase Loss – Phase failure or unbalanced voltage between the inverter supply phases, inverter displays Lin.

First step from the service manual

Using a voltmeter check supply voltage from L1, L2 and L3 phase to ground; should have between 110-125 volts, readings within +/- 2 volts of each other.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What A-b means on a Continental washer

The A-b error code on a Continental washer indicates an Input Phase Loss condition. This fault is triggered when the inverter driving the wash motor detects a failure or significant voltage imbalance across one or more of the three supply phases (L1, L2, and L3). When the inverter detects this condition, it displays "Lin" as an internal indicator. Three-phase power is required to keep the inverter operating correctly, and any interruption or imbalance in that supply will halt motor operation and generate this fault.

The inverter monitors the incoming voltage on all three legs of the supply. Each phase should read between 110 and 125 volts measured to ground, and all three readings should fall within plus or minus 2 volts of each other. If one phase drops out entirely due to a blown fuse, a tripped breaker leg, or a failed connection, the voltage on that leg will read significantly lower than the others or show zero. A utility supply issue, a loose terminal at the machine's terminal block, or a failing contactor can each produce the same out-of-tolerance reading that triggers A-b.

Because this fault originates in the incoming power supply rather than in the washer's internal electronics, the first diagnostic priority is always to verify the supply voltage at the machine before condemning any internal components. Use a calibrated voltmeter to measure L1, L2, and L3 individually to ground, then compare all three readings. Unbalanced or missing phases must be corrected at the power source or in the wiring before the inverter can resume normal operation.

Source: manufacturer service documentation.

Common causes of A-b

  1. 01

    Tripped or blown breaker leg

    Wiring / connection

    A single leg of the three-phase circuit breaker may have tripped or an associated fuse may have blown, dropping one phase to zero volts. Check the breaker panel and measure voltage at each phase before proceeding further.

  2. 02

    Loose or corroded supply terminal

    Wiring / connection

    A loose connection at the washer's input terminal block or at the disconnect can cause one phase to read low or intermittently drop out. Inspect all terminals for tightness and signs of arcing or oxidation.

  3. 03

    Utility supply imbalance

    Wiring / connection

    The incoming three-phase power from the utility may be unbalanced, with one phase outside the 110-125 volt range or more than 2 volts away from the others. Contact the utility provider or measure at the service entrance to confirm.

  4. 04

    Faulty or worn contactor

    Part replacement

    A contactor in the supply circuit with pitted or worn contacts can create high resistance on one leg, causing a measurable voltage drop under load that triggers the phase loss fault.

  5. 05

    Damaged supply wiring

    Part replacement

    A broken conductor or damaged wire between the disconnect and the machine's terminal block can interrupt one phase entirely. Inspect wiring for visible damage, pinching, or failed splices.

See the test procedure for each cause

Frequently asked questions about A-b

What does A-b mean on a Continental washer?
The A-b code means the washer's inverter has detected an input phase loss, meaning one or more of the three incoming power phases has failed or become significantly unbalanced. The inverter will also display "Lin" to indicate this condition internally. The machine shuts down to prevent damage to the motor and inverter electronics. The fault must be diagnosed starting with a voltmeter check of all three supply phases.
Can I reset the A-b error code to get my Continental washer running again?
Resetting the machine without correcting the underlying power supply problem will not permanently clear the A-b fault. The inverter will detect the same phase imbalance or loss as soon as it attempts to run and will re-trigger the error. The supply voltage issue must be identified and corrected first, after which the fault should clear on its own.
Is it safe to use my Continental washer while the A-b code is active?
No, the washer should not be operated while A-b is active. The machine has already shut itself down because it detected unsafe power conditions. Running the washer with a missing or unbalanced phase can cause serious damage to the inverter and motor. Do not attempt to bypass or override the fault.
How do I fix the A-b error code on a Continental washer?
Start by using a voltmeter to measure the voltage from L1, L2, and L3 to ground at the machine's supply terminals. Each reading should fall between 110 and 125 volts, and all three should be within plus or minus 2 volts of each other. If a phase is missing or out of range, trace the fault to the breaker, disconnect, supply terminals, or wiring and correct the problem. If the supply voltage checks out correctly at all three phases, the inverter itself may require further evaluation.
How much does it cost to repair an A-b error code on a Continental washer?
Repair costs depend entirely on what is causing the phase loss. If the fix is a reset tripped breaker or a tightened terminal connection, the cost may be minimal, covering only a service call in the range of 75 to 150 dollars. Replacing a faulty contactor typically adds 50 to 150 dollars in parts. If the inverter has sustained damage from prolonged phase loss operation, inverter replacement can range from several hundred to over a thousand dollars depending on the unit.

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