Product Overview
A&M 4951-381 Analog Power Factor Panel Meter - Ruggedized Watertight Housing, LAG/LEAD Scale
Condition
Used, clean, and in good condition with scuffs and paint chips on the housing from normal use and storage - visible on the lower-left corner and side edges. Both hex panel studs are intact. Stud terminals (marked 3 and 5) and molded port numbers 1-5 are present. Continuity tested only - we do not have the means to perform further functional testing. No manuals or accessories are included. Sourced from a government research facility.
Carefully packed and shipped same business day from our Idaho warehouse. Online since 1999. Honest equipment and straightforward service.
No hassle resolution if there is an issue. Serving customers since 1999.
Product Overview
A&M Instruments Model 4951-381 analog power factor panel meter. Built to the ruggedized 4951 series standard, designed for panel mounting in demanding environments with a watertight housing. Measures power factor in AC electrical systems, displaying the relationship between real power and apparent power on a LAG/LEAD analog scale. The 4951 series is built to meet military specifications MIL-M-19261 and MIL-M-16034, with panel mounting conforming to MIL-PRF-10304F. Intended for integration into switchgear, distribution panels, control cabinets, and generator sets.
Key Features
- Analog power factor meter with LAG/LEAD needle display - 0.7 to 1.0 range visible on dial face
- Watertight housing construction
- Panel mount configuration - conforms to MIL-PRF-10304F
- Built to military specifications MIL-M-19261 and MIL-M-16034 (ruggedized series)
- Cream/gray painted housing with stud terminals - ports 1-5 molded, terminals 3 and 5 visible and intact
- Two hex panel studs and slotted mounting screws present
- AC electrical system measurement - suitable for linear load applications
- Potential input voltage 85-135VAC, current input 0.001-5AAC, 60Hz (not confirmed for this specific suffix - verify against datasheet before use)
Applications
- Switchgear and electrical distribution panel integration
- Generator set monitoring and control panels
- Industrial facility energy management and power quality monitoring
- Military and marine panel installations requiring watertight construction
- Replacement meter in existing 4951-series panel builds
Frequently Asked Questions
What testing was performed on this meter?
Continuity testing only. We do not have the equipment or expertise to perform full functional power factor testing. Buyers who require confirmed calibration or functional verification should plan to test before installation.
Is this unit self-contained or does it require an external transducer?
Not confirmed for this specific suffix. The A&M 4951 series can be supplied as self-contained or as a matched set requiring an external transducer. Verify the configuration against the suffix code or original system documentation before ordering.
What are the input voltage and current requirements?
Not confirmed for the 4951-381 suffix specifically. The broader 4951 series is associated with 85-135VAC input and 0.001-5AAC current input at 60Hz - verify against datasheet before use to confirm this unit's actual ratings.
What is included with this meter?
One meter unit as pictured. No manuals, cables, or accessories are included.
Is this meter suitable for systems with harmonic distortion or non-linear loads?
Not recommended. Analog power factor meters of this type measure phase shift for linear loads. Systems with significant harmonic distortion - such as those driven by rectifiers or switching power supplies - require a true RMS or digital power quality meter for accurate readings.
Military-spec ruggedized construction, a watertight case, and a clean LAG/LEAD needle - this meter was built for panels that had to work under real conditions. Wherever it goes next, it carries that lineage with it.
