Beckwith M-0115A Transformer Parallel Balancing Module

Beckwith M-0115A Transformer Parallel Balancing Module

Product basic positioning

1. Core role

Beckwith Electric (a subsidiary of Hubbell Group) M-0115A is a dedicated module for on load regulating LTC transformer circulating current method parallel balancing, which is used in conjunction with regulating controllers such as M-0067E and M-2001C/D. It achieves synchronization of the connection gear and suppresses parallel circulating current when multiple L transformers are running in parallel, and complies with the parallel specification in section 10.2 of ANSI C57.12.10-1988.

2. Resolve core pain points

There are two common issues with voltage regulation of parallel transformers:

Sensitivity too high → frequent back and forth gear shifting (oscillation hunting);

Sensitivity too low → There are many differences in the tap positions of each transformer, and the circulating current exceeds the standard.

This machine achieves a perfect balance between two working conditions through 9-level adjustable circulating current sensitivity, and is suitable for complete sets of new transformers and retrofitting of old substations.

3. Qualifications and Quality Assurance

UL Industrial Equipment Certification (4F84);

5-year warranty for the entire machine;

Compliant with ISO9001:2015.

Electrical input and winding parameters

1. Basic electrical specifications

Rated 0.2A, 50/60Hz, winding rated load 12VA, iron core unsaturated at 12VA.

2. Short term overload tolerance of winding (K1/K2/ACT winding)

Continuous: 0.4A;

5 seconds: 2.9A; 4 seconds: 3.3A; 3 seconds: 4.0A; 2 seconds: 5.0A.

3. Input/output anti-interference and isolation

Meets ANSI/IEEE C37.90.1 oscillation and fast transient surge immunity standards, with no component damage or erroneous instructions during faults;

All circuits have a ground withstand voltage of 1500Vac/1min; Each winding is completely isolated electrically, with no crosstalk.

Front panel dual adjustment knob function

Parallel/INDEPENMENT mode switch (43P)

Parallel mode: Transformers run in parallel, with circulating current balance correction activated, and the controller tracks the gear uniformly;

INDEPENMENT (independent mode): Exit parallel balancing and adjust the voltage of each transformer separately;

⚠️  Important warning: When the transformer is automatically controlled in parallel with load, it is strictly prohibited to switch to INDEPENDEN, as it will lose the function of circulating current monitoring and gear synchronization.

SENSITIVITY Circulation Sensitivity Adjustment Knob (43S, 9-speed adjustable)

Based on gear N, there are a total of 4 gears on both sides: the adjustment range is 0.5 to 2 times the standard sensitivity;

More Sensitive (right): More sensitive, with small circulation triggering gear correction, suitable for scenarios with strict requirements and small circulation limits;

LESS SENSITION (left): Reduce sensitivity to avoid voltage fluctuations caused by slight load fluctuations.

Backplane terminals and internal winding structure

1. Terminal TB1 (No. 1-10, compatible with 22-16AWG cables)

Tightening torque of wiring screws: 4.8 inch pounds; Internal 3 sets of isolated windings:

K1, K2: Load current collection winding of each transformer;

ACT circulating current correction winding: with multiple taps to achieve 9-level sensitivity grading;

Auxiliary contacts 43S (sensitivity switching) and 43P (parallel/independent mode) are used for circuit switching.

2. Internal principles

Collect the secondary 0.2A current of each parallel transformer CT, compare and generate a circulating current correction signal output to the matching LTC controller, automatically correct the tap changer position, and eliminate parallel circulating current.

Physical and installation specifications

1. Dimensional parameters

Whole machine: Height 25.4cm x Width 16.19cm x Thickness 11.35cm;

Standard panel opening: 21.59cm x 15.56cm;

After selecting the M-0124 surface mount adapter, the maximum thickness is 11.59cm.

2. Weight

Net weight 2.7kg, transportation weight 3.4kg.

3. Environmental tolerance

Working temperature: -40 ℃~+80 ℃, maintaining nominal accuracy throughout the entire temperature range;

Humidity: up to 95% without condensation, with no change in accuracy;

PCB sprayed with anti mold coating, suitable for humid and dusty environments in substations.

On site matching and renovation adaptation requirements

1. Controller matching prerequisite

This machine requires the voltage regulator controller to have dual current inputs of 0.2A load CT and 0.2A circulating current CT:

The original controller has a 5A CT input: the M-0067E/M-2001C/D controller must be replaced;

On site CT is 5A: Install M-0169A 5A to 0.2A auxiliary CT;

Two phase voltage supply scenario: M-0067E requires modification of M-0169A terminal, while M-2001 comes with phase correction.

2. Wiring rules for auxiliary contacts of circuit breakers

There are segmented switches, line 52 switches, and bus tie 24 switches: use switch auxiliary contacts to automatically switch between parallel/independent modes; Activate parallel logic when all switches are closed;

Only shared load switch, no segmented switch: only connected to normally closed contacts, not connected to normally open circuits.

3. Manual load switching operation specifications

Before using the manual load switch, M-0115A must be switched to INDEPENMENT independent mode to prevent the circulation control logic from failing.

Supporting materials and specifications

Complete system manual: "LTC Transformer Voltage Regulating with Parallel and Backup Control System", available for download on the official website, including typical primary wiring, CT configuration, and complete parallel circuit diagram;

Compliance basis: ANSI C57.12.10-1988 Standard for Parallel Operation of Transformers.