Jiangsu Acrel Electrical Manufacturing Co., LTD.
Jiangsu Acrel Electrical Manufacturing Co., LTD.

Application of ASJ Residual Current Relay in a Generator Set Project in the Maldives

The necessity of applying residual current, the main functions, working principle, classification situation of ASJ residual current relay are introduced, and the principles and precautions in selecting residual current protection circuit breaker are indicated. This is a brief introduction about the addition of our company application of ASJ residual current relay in a generator set project in the Maldives.

Keywords: ASJ residual current relay; generator set; application.


1. Project overview

This project is located in the Maldives. The purpose of the residual current relay installed is to detect the residual current and compare the residual current value with the base value. When the residual current value exceeds the base value, it will send out a mechanical on-off signal (to make the mechanical switch tripped or the acousto-optic alarm device sends out an alarm). Residual current relay usually with low voltage circuit breaker or low voltage contactor, etc combined residual current protection device, mainly applied to ac 50 Hz, rated voltage 400 v and below the TT and TN system distribution circuit, used to ground fault protection electric circuit, prevent equipment damage caused by ground-fault current and electrical fire accident, also can be used to provide indirect contact to a person get an electric shock risk protection, and therefore is widely used in low voltage power supply and distribution system.


2. Main uses of residual current relay

2.1 Protection of Indirect Contact Electric Shock

The measure of indirect contact electric shock protection is to automatically cut off the power supply. GB 13955" the protection of indirect contact electric shock accident "stipulates": the main measure of indirect contact electric shock accident protection is to adopt the protection mode of automatically cutting off the power supply to prevent the damage accident caused by the insulation damage of electrical equipment. When the circuit insulation damage is caused by a grounding fault. When the fault current value is less than the operating current value of the over-current protection device, the residual current protection device shall be installed ." According to the research, the safe value of contact voltage is 50V. For personal safety, when insulation failure occurs in any part of the electrical device, once the contact voltage exceeds 50V, it is necessary to automatically cut off the fault part of the power supply within the specified time. The over-current protection device is limited by the electrical circuit and equipment and its own action value, and can not automatically cut off the power supply. The residual current protection device is not affected by the load current and can be used in conjunction with the over-current protection device for indirect contact electric shock protection.

2.2 Ground fault protection

Grounding is the contact between a live conductor and the earth, a grounded metal shell, or a component connected to the ground. Its failure may lead to personal electric shock casualties and equipment damage and may cause an electrical fire in serious cases. Ground fault protection used to be protected by over-current protection devices. When the grounding fault current is greater than the fixed value of the over-current protection device, the fault circuit is cut off by the over-current protection device.

In TT system, the line with larger rated current and longer distribution line, grounding fault of live conductor, unsafe metallic grounding fault and arc grounding fault in TN system may occur that the grounding fault current is less than the set current of over-current protection action, and the over-current protection device does not act. Residual current protection device, or circuit breaker with ground fault protection, can reliably carry out ground fault protection.

2.3 Electrical fire protection

Electrical fire is usually caused by an electrical short circuit, which includes a metal short circuit and an arc short circuit. The former is a short circuit between live conductors (such as between phases, between phases and N lines). The fault current is calculated in kilo ampere. High temperature is easy to cause insulation oxidation and spontaneous combustion.

Although the fire hazard is great, it can be protected by circuit breakers and fuses with short circuit protection, and the power supply is cut off by instantaneous action of the circuit breaker to avoid fire. The latter is a live conductor short circuit to the ground, mostly arc as the path, although the fault current is small, on the one hand, the arc lasts for a long time, the local temperature is high, it is easy to ignite the surrounding combustible material and cause a fire. Therefore, the fire hazard caused by an arc short circuit is much greater than that of a metal short circuit. The circuit breaker with residual current action protection function can cut off the support circuit without the operation of the over-current protection device to prevent the electrical fire caused by the arc short circuit.


3. ASJ Series of Residual Current Relay

3.1 Model & Function

Mode

FunctionInstallation methodPicture

ASJ10-ID1c

AC type residual current measurement

Current over-limit alarm indication; rated residual action current can be set; no drive time can be set; two sets of relay output; local and remote "test" and "reset" functions;

Guide rail (DIN35mm)

ASJ10-ID1C Power Sensor

ASJ10-ID1A

Type A residual current measurement;

Current percentage light column display; rated residual action current can be set; no drive time can be set; two sets of relay output (can be set); local and remote "test" "reset" function;

ASJ10-ID1A Power Monitoring Device

ASJ10L-LD1

Type A residual current measurement;

Rated residual action current can be set; no drive time can be set; transformer disconnection alarm can be set; two sets of relay output (can be set); pre-alarm value can be set: return value can be set; with local and remote "test", "reset" function; 25 events Record;

ASJ10L-LD1 Power Monitor

ASJ20-LD1C

Ac type residual current measurement;

Current over-limit alarm indication; rated residual action current can be set; no drive time can be set; two sets of relay output; local and remote "test" and "reset" functions;

Screen mount (48 square)ASJ20-LD1C Power Monitoring Unit
ASJ20-LD1A

Type A residual current measurement;

Current percentage light column display; rated residual action current can be set: no drive time can be set; two sets of relay output (can be set); with local and remote "test", "reset" function;

ASJ20-LD1A Power Quality Monitoring Devices
TypeBasic Function

Installing

Photo

ASJ10-LD1C

Measurement ofAC-type after-current; Indicator of current off-limit alarm; The setting of rated residual action current ( see in table 2); The setting of non-driving time of limitation ( see in table 2);

Two-pair relay output; Possessing the function of on-the-spot and long-distance testing and resetting

DIN RailTS35mm

ASJ10-LD1C Power Monitoring Unit

ASJ10-LD1A

The measurement of-type after-current; The streamer display of current percentage; The setting of rated residual action current ( see in table 2); The setting of non-driving time of limitation ( see in table 2); Two- pair relay output(both of which can be set)*; Possessing the function of on-the-spot and long-distance testing and resetting.

ASJ10-LD1A Power Quality Monitoring Devices

ASJ20-LD1C

The measurement of A-type after-current; The streamer display of current percentage; The setting of rated residual action current ( see in table 2); ASJ2O-LD1 The setting of non-driving time of A limitation ( see in table 2); Two-pair relay output(both of which can be set)*; Possessing the function of on-the-spot and long-distance testing and resetting

Screen structure 48 square

ASJ20-LD1C Energy Management

ASJ20-LD1A

The measurement of-type after-current; Thestreamerdisplay of current percentage; The setting of rated residual action current ( see in table 2);

The setting of non-driving time of limitation (see in table 2); Two- pair relay output(both of which can be set)*;

Possessing the function of on-the-spot and long-distance testing and resetting


ASJ20-LD1A Energy Management System

ASJ10L-LD1A

A residual current measurement; Rated residual operating current can beset (see 8.1); Limit non-drive time can be set (see8.1); Two sets of relay outputs,(see 8.1); Transformer break alarm can be set(see 8.1) Pre-warning values are available (see 8.1); A return value can be set (see 8ASJ10L-LD1A programming menu instructions); In situ, Remote test, reset function; 25incident records

DINRail

TS35mm

ASJ10L-LD1A Energy Management Solutions


3.2 Technical Parameters

technical parameterIndex
Type ACType A
input

Rated residual action current I△n

0.03、0.1、0.3、0.5(A)

0.03、0.05、0.1、0.3、0.5、1、3、5、10、30(A)

Non-driving time of limitation △t

0.1、0.5(S)

0、0.06、0.1、 0.2、 0.3、0.5、0.8、1、4、10(s)

Rated residual non-action current I△no

50%I△n

50%I△n

performance characteristics

simple sinusoidal alternating current

simple sinusoidal alternating current and pulsating direct current

frequency

50Hz±5Hz

50Hz±5Hz

action error

-20%~-10%I△n

-20%~-10%I△n

outputoutput modeone is the normal closing and the otherone is the normal closing or opening, and the other is for the transformation


technical parameterIndex
Type ACType A
input

Rated residual action current I△n

0.03、0.1、0.3、0.5(A)

0.03、0.05、 0.1、0.3、 0.5、1、3、5.10、30(A)

Non-driving time of limitation△t

0.1、0.5(s)

0、0.06、0.1、0.2、 0.3、0.5、 0.8、1、4、10(s)

Rated residual non-action current I△no

50%I△n

50%I△n

performance characteristics

simple sinusoidal alterating current

simple sinusoidal alternating current and pulsating direct current

frequency

50Hz±5Hz

50Hz±5Hz

action error

-20%~-10%I△n

-20%~-10%I△n

output

output mode

one is the normal closing and the other

one is the normal closing or opening, and the other is for the transformation


3.3 Typical Application Schematic

Application of ASJ Residual Current Relay in a Generator Set Project in Maldives


4. Pictures of the installation of the residual current relay on the generator set project site

Application of ASJ Residual Current Relay in a Generator Set Project in Maldives

Other Asia Microgrid Energy Management System Cases