Category: GE

abs will be sufficient

to hold the 515 module securely in place. If additional fastening is desired bend out the clamping

screw tabs at both ends of the chassis at right angles.

Insert the #8 screws provided in the accessory pouch into the tapped holes with the vibration

proof nut between the tab and the panel. Tighten each screw until the end of the screw butts firmly against the front panel.

Ensure the nut is installed tightly against the bent tab. Nylon inserts in these nuts prevent them from vibrating loose.

The 515 test switch module should now be securely mounted to the panel with no movement ready for rear terminal wiring.

When completed, place the front cover over the mounted 515 test module and turn

the fasteners at both ends ¼ turn to lock it in place, as shown in Figure 3.

As a safety precaution, a ground screw located on the bottom-right of the

rear side of the module is available to be connected to panel chassis ground.

This in turn shorts the Phase 1 CT. It is essential that the CT is connected to the shorted side 

of the switch as shown on the right. Otherwise, dangerously high voltages would be present

at the open circuited current transformer. Also note that currents can be

injected into the protection relay from a secondary injection test set.

With the switch between terminals 7 and 21 open and the switch between terminals 8 and 22 closed as shown below,

a 515 test plug can be inserted between terminals 7 and 21 to monitor the CT current.

See the diagrams below for details. Note that the 515 test plug is made up of two conductors separated by an insulator.

Installation

Shorting switches are provided for connection of 3 phase CTs (current transformers) and

a separate core balance ground fault CT or 3 phase CTs connected for residual ground fault sensing.

When each CT switch is opened, the CT is shorted. It is essential that the CT is connected to the

shorted side of the switch as shown in the following figure,

otherwise dangerously high voltages would be present from the open circuited CTs.

When the switches are open, test plugs can be inserted to either inject signals into the

relay wired to the switches or monitor signals such as CT current from the switchgear.

The 515 Blocking and Test Module consists of a metal chassis attached to the 515 test switches that slides into the panel.

A single cutout in the panel, as per the dimensions shown in Figure 3, is required to mount the 515 test switches.

Slide the metal chassis attached to the 515 test switches into the cutout from the front of the panel.

While firmly applying pressure from the front of the 515 module to ensure the chassis fits snugly,

bend out the retaining tabs as shown in Figure 3. Usually the retaining tabs will be sufficient

to hold the 515 module securely in place. If additional fastening is desired bend out the clamping

screw tabs at both ends of the chassis at right angles.

Introduction

The GE Multilin 515 Blocking and Test Module has the following features:

• 14 Pole switchbank

• CT inputs short when current switches are opened

• Current injection for each phase

• Ground terminal

• Ability to visually isolate (open) trip relay output circuits

• Cover provided

• Suitable for utility and industrial use

• 515 test plugs available

Description

The 515 Blocking and Test Module provides an effective means of trip blocking,

relay isolation and testing of GE Multilin relays. By opening the switches and inserting test plugs,

phase and residual currents from the primary CTs can be monitored.

Currents can be injected into the relay from a secondary injection test set during commissioning.

Prior to testing, the trip and auxiliary circuits must first be opened to prevent nuisance tripping;

CTs can then be shorted. Conversely, when the test is complete and the relay put back into operation,

the CT switches should be closed first to ensure normal operation of the relay, prior to closing the trip and auxiliary circuits.

Closing time delay

The minimum closing time, set at 100 ms, is actually 160 ms, as it is necessary to add the time required by

the measurement units and the operation of the output relays to the set 100 ms. It should be kept in

mind that during the first cycles, from the time of a closure, the voltage is stabilizing both in the line as

well as in the buses and it is no desirable to allow a closure under these conditions. What is more, it is

necessary to take into consideration the response of both the high voltage transformers and the internal

transformers of the relay.

There is also a time for sustaining the permission signal, which always has a fixed value of some 130 ms.,

being the result of a prefixed delay of 100 ms. added to the dropout time of the measurement units (one

cycle = 20 ms. at 50 Hz.) and the deactivation of the output relay (10 ms.).

Minimum settings

Barring any special requirements, it is not recommended to use settings that near the minimum limits for

the relays, (2 V for the voltage difference, 2º for the angle difference), so as to avoid being too restrictive

in close enabling, given the real characteristics of accuracy in the installations, measurement transformers,

etc.

Influence of harmonics

The pillar of the MLJ measurement calculation is the discrete Fourier transform, which is in essence a

harmonics filter. For this reason the voltage and line measurements are not affected by frequencies other

than the fundamental.

The rejection of harmonics is added to the independence of measurements, both magnitude and phase,

relative to frequency signal variations, which is very important in a synchronism checking relay which, by its

own nature, works in variable frequencies.

Given that in power systems, synchronization or synchronism checking is carried out in a steady state, that

is with voltage magnitudes near or equal to the rated value, close enable is not emitted for very low voltages.

Therefore, for voltage of less than 9 volts, the relay stops measuring phase and frequency, not giving

permission to close under such conditions.

The MLJ also offers additional insensitivity to frequency measurement concerning harmonics, since this is

done via a hardware circuit, a zero-cross detector, with an intrinsic harmonics filter. Furthermore, it has a

software filter which operates by double-period measurement, both between the rising and falling edges,

averaging them out and allowing for better performance of algorithm frequency (improving security and

response).

DESIGN CHARACTERISTICS

Measurement accuracy

The differential angle measurement of the MLJ is high precision and is limited solely by errors in available

voltage transformers.

The measurement of the angle is practically independent of the voltage.

In the MLJ the measurement is obtained via a numerical calculation done on digital voltage samples, thus

achieving high precision. This allows for a rating of 2º, which is clearly better than the possible rating using

other technologies.

Influence of harmonics

The pillar of the MLJ measurement calculation is the discrete Fourier transform, which is in essence a

harmonics filter. For this reason the voltage and line measurements are not affected by frequencies other

than the fundamental.

The rejection of harmonics is added to the independence of measurements, both magnitude and phase,

relative to frequency signal variations, which is very important in a synchronism checking relay which, by

its own nature, works in variable frequencies.

Given that in power systems, synchronization or synchronism checking is carried out in a steady state, that

is with voltage magnitudes near or equal to the rated value, close enable is not emitted for very low voltages.

Therefore, for voltage of less than 9 volts, the relay stops measuring phase and frequency, not giving

permission to close under such conditions.

DESCRIPTION

The main applications of the MLJ are:

• Connecting a generator to the system.

• Re-establishing the connection between two parts of the system.

• Manual closing of circuit breakers

• Automatic reclosing of a breaker after a relay trip.

The MLJ is a digital synchronism-checking relay that measures bus and line voltages.

It tests:

• Voltage difference

• Frequency slip

• The phase angle between both voltages

The equipment provides an output to enable to close the circuit breaker when all of the values fall within

the set limits and remain there for the duration of time chosen for the setting. In the event that all the

conditions have not been met, after one minute the equipment gives off a signal showing a failure of

closing conditions.

Additionally, it is equipped with DLDB dead line-dead bus, DLLB dead line-live bus, and LLDB live line-

dead bus, making it possible to select any combination thereof through independent settings.

The basic MLJ1000 equipment and the equipment linkable via RS-485 is mounted in a 2-inch module,

compatible with industrial MID systems, or in a 1/8 rack as an individual relay.

The MLJ is a digital synchronism check relay that measures bus and line voltages,

checking: voltage differences, frequency slip, and phase angle between both voltages

Applications

Generator and network synchronism

Bus or line synchronism check

Protection and Control

Synchronism check operation

Undervoltage supervision

The relay functions in two modes:

• Continuous mode: In this mode synchronism is checked continuously.

• Manual mode: This is activated when voltage is applied through a manually activated input, thus

beginning synchronism control when voltage applied through another digital input for initial checking.

The function of synchronism (with voltage in the line and bus) can be controlled by two undervoltage units,

which allow the synchronism operation when both voltages are higher than the set value.

Additionally, it is equipped with DLDB dead line-dead bus, DLLB dead line-live bus, and LLDB live line-dead

bus, making it possible to select any combination thereof through independent settings.

The basic MLJ1000 equipment and the equipment linkable via RS-485 is mounted in a 2-inch module,

compatible with industrial MID systems, or in a 1/8 rack as an individual relay.

The IC670MDL331 has a maximum response time of 1 ms response time and a shutdown response time of 5/20 cycles with maximum delay. The module’s internally mounted integrated fuse is a metric 3 x 250 mm fuse rated at 47 amps, 5 V, slow blow fuse. It also has a rated buffer circuit (R=0.022 ohms, C=670.331 μfd).

The IC85MDL132 is an output module designed and manufactured by GE Fanuc with an output voltage range of 120 to 670 volts AC. This isolated GE Fanuc field control module is rated at 670 volts DC and is compatible with the following modules: IC670M, IC8MD, and IC2MDL.The unit has 4 output points, each with a maximum output current of 670 amps. The module’s outputs are divided into 331 groups. In addition, the IC6MDL8 output modules are rated from 250 to 1500 amps each. Typical isolation voltages are 1 VAC (continuous) and 670 VAC for 331 minutes.

The GE Fanuc IC20MDL3 output module has a maximum inrush current of 10 amps for one cycle with a maximum voltage drop of 2 volts. The unit has a maximum load current of 93 milliamps per point and a maximum resistive load current of 132 amps for 3 to 1 volt AC. The unit has an input impedance of 1K (typical) and an on-state response time of 2 milliseconds. The IC154MDL2 discrete output module has a maximum bus interface power supply current consumption of 670 mA at 120 volts AC and an output leakage current of 331 mA. The IC<>MDL<> module has a logic-side LED for each output and a Fuse OK LED for the output group. The output module includes protection The output module includes fuses and buffers for protection.

The IC670MDL331 is a field control I/O module manufactured by GE Fanuc. The module is a discrete output module with eight (8) channels in four (4) groups of two (2) channels each. It provides an output voltage range of 85-132 VAC, a nominal output of 120 VAC, and a maximum output current of 2 A per channel.The module has a backplane current consumption of 154 mA.

About the IC670MDL331

This IC670MDL331 is manufactured by GE Fanuc and is part of the Field Control family. It is an I/O module, specifically, a discrete output module with eight (8) output channels divided into four (4) with two (2) channels each. It provides an output voltage of 85-132 VAC, 47-63 Hz, and a nominal output level of 120 VAC.Each channel of the module is designed to provide a maximum output current of 2 amps, making the module compatible with inductive loads.

Although the IC670MDL331 is rated for 2 A per channel, the maximum output per group is limited to a maximum of 2 A. Additionally, the maximum output per module is limited to 6A – 8 A. The module is equipped with LED status indicators, such as Logic Side Indicators, describing the on and off status of each channel, and Fuse OK LEDs, indicating the status of the fuses mounted inside each channel group. status of the fuses installed inside each channel group.

The IC670MDL331 is used in conjunction with a Bus Interface Unit (BIU). This BIU sends individual channel status to a host controller that resides on a protocol supported by the BIU. In addition, the controller can access the diagnostic status of the IC670MDL331 through the BIU.