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Miller 161078 Supplementary Protector, Man Reset — main product image
Miller 161078 Supplementary Protector, Man Reset
Miller 161078 Supplementary Protector, Man Reset
Miller 161078 Supplementary Protector, Man Reset
Miller

Miller 161078 Supplementary Protector, Man Reset

1-pole, 7A manual-reset supplementary protector rated to 250Vac delivers reliable branch circuit protection in compact industrial panel configurations.

$73.99*
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*Price sourced from Amazon.com. Last updated:Jun 28, 2026.Price and availability are subject to change.

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Overview

The Miller 161078 is a single-pole supplementary protector with a manual reset mechanism, rated at 7 amperes and 250Vac. Its role in a control circuit is specific: supplementary protectors are placed downstream of a listed branch circuit breaker to provide component-level or sub-circuit overcurrent protection within a control enclosure or piece of equipment. The 7A rating addresses the protection needs of small fractional-horsepower motors, control transformers, and instrumentation sub-circuits common in industrial automation panels. The manual reset design is not a limitation — it is an intentional safety feature ensuring that an overcurrent event requires human acknowledgment before the protected circuit is re-energized.

From a procurement and integration standpoint, the 161078 is a compact device suited to panel builders who need individual circuit protection at the component level without the footprint of a full molded-case breaker. The 1-pole configuration and standard supplementary protector form factor are compatible with typical DIN rail or panel-mount installations. Facilities engineers specifying this device should confirm interrupt capacity against available fault current at the installation point and verify that the application correctly calls for supplementary rather than primary overcurrent protection per the applicable electrical code. As with all electromechanical protection devices, inclusion in a documented periodic maintenance and functional test schedule is recommended to ensure trip mechanism integrity over the device's service life.

Key Features

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Specifications

Model
161078
Type
Supplementary Protector
Reset Type
Manual Reset
Poles
1P (Single Pole)
Amperage Rating
7A
Voltage Rating
250Vac

Pros & Cons

👍 Pros

  • Manual reset prevents automatic circuit restoration after a trip event, enforcing deliberate human review before power is restored.
  • 1-pole, 7A, 250Vac ratings cover a broad range of fractional-horsepower motor and control circuit protection needs in industrial panels.
  • Compact supplementary protector form factor integrates into control enclosures with minimal panel space requirements.
  • Single-pole configuration allows individual protection of sub-circuit conductors without over-specifying for the load.

👎 Cons

  • Rated as a supplementary protector, not a UL 489 branch circuit breaker — cannot substitute for primary overcurrent protection at the panel level in NEC-governed installations.
  • Miller publishes minimal publicly available datasheet documentation for the 161078, making interrupt capacity and trip curve verification difficult without direct vendor contact.
  • 1-pole configuration limits use to single-phase or single-conductor control circuit applications — not suitable for multi-phase protection without additional devices.
  • Manual reset requires physical access to the panel on every trip event, which may increase downtime in unmanned or remotely monitored installations.

Frequently Asked Questions

The Miller 161078 is rated at 7A and 250Vac, configured as a 1-pole supplementary protector. It is designed for branch circuit supplementary protection in industrial and commercial control panel applications — not as a primary branch circuit breaker under NEC Article 240 definitions.
A supplementary protector is intended to provide overcurrent protection for individual components or sub-circuits within equipment — not for general branch circuit protection at the service entrance level. It supplements, but does not replace, a listed branch circuit breaker. Verify that your application does not require a UL 489 listed molded case circuit breaker in place of this device.
Manual reset means the protector will not automatically restore circuit continuity after a trip event. An operator must physically actuate the reset mechanism to restore power. This is the correct behavior for applications where automatic restart could create a safety hazard following an overcurrent condition.
The 161078 is a 1-pole device, protecting a single conductor. Interrupt capacity and exact trip curve characteristics should be confirmed in Miller's product datasheet for the specific installation environment and fault current levels expected at the installation point.
Supplementary protectors are electromechanical devices subject to mechanism wear over time. While no periodic calibration in the metrology sense is required, operational testing at defined intervals per the facility's maintenance program is recommended to verify that the trip mechanism actuates correctly at rated overcurrent.

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