| Driving Power Supply Fault | Driving power Supply Fault for Model G250T4 and above |
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ERR37 – Driving Power Supply Fault
What this means
ERR37 indicates a failure in the internal driving power supply on the VFD’s driver board. This supply powers the circuitry that actually drives the motor output stages.
In simple terms:
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The VFD’s internal drive electronics are not receiving proper power
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The VFD cannot safely control the motor
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The VFD shuts down to prevent further damage
This fault applies to Model G250T4 and above and is not caused by cutting load or configuration.
What the Driving Power Supply Does
The driving power supply feeds:
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Gate driver circuits
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Output transistor control logic
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Isolation and protection circuitry
Without this supply operating correctly, the VFD cannot safely switch power to the motor phases.
Most Common Causes
1. Internal power supply failure
The most common cause.
Possible reasons:
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Component aging
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Electrical stress
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Heat-related degradation
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Prior over-voltage or short events
This is an internal hardware issue.
2. Power surge or brownout damage
External power issues such as:
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Voltage spikes
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Unstable mains power
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Improper grounding
Can damage internal power supply components over time.
3. Secondary failure after another fault
ERR37 may appear after:
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Over-current faults
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Short-to-ground events
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ERR17, ERR31, ERR33, or ERR35 events
In these cases, the driving power supply may have been damaged as a result of the original issue.
What to Check First
Step 1: Fully power cycle the VFD
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Power off the VFD
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Disconnect input power
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Wait at least 3 minutes
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Restore power and observe
If ERR37 clears briefly and returns, internal failure is likely.
Step 2: Verify incoming power
Confirm:
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Input voltage is correct for the VFD
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No loose mains connections
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Proper grounding
While this will not repair the fault, it rules out external contributors.
What Will Not Fix ERR37
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Changing feeds or speeds
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Adjusting acceleration or deceleration
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Re-running motor identification
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Rewiring the motor
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Changing parameters
ERR37 is not user-tunable.
When to Contact Support
If ERR37:
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Appears immediately at power-up
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Returns consistently after power cycling
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Prevents the VFD from enabling
Please contact support with:
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VFD model
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Approximate age
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Any recent electrical events or prior faults
In most cases, ERR37 indicates an internal hardware failure requiring repair or replacement.
Summary
ERR37 means the VFD’s internal driving power supply is not operating correctly.
Most common causes:
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Internal power supply failure
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Electrical stress or prior fault damage
This is a hardware-level issue, not a setup or usage problem.
