Background Image
Table of Contents Table of Contents
Previous Page  181 / 211 Next Page
Information
Show Menu
Previous Page 181 / 211 Next Page
Page Background

T ECHN I CAL DATA

C I RCU I T P ROT ECT I ON

181

APPLICATIONS

l

RCBOs provide both earth fault and over current protection. The MCB

element of Starbreaker and Loadstar devices are available as Type B or Type C

making them suitable for domestic or light commercial applications. These

Type A Voltage dependent devices are single pole with solid neutral one

module wide (18mm) with a flying lead. During interruption of the neutral

conductor the protective function is guaranteed when FE and PE conductors

are connected. The use of Starbreaker and Loadstar 30mA RCBOs provides

independent RCD protection to individual circuits offering both the degree of

additional protection that may be required by Regulation 415.1 and the

minimum of inconvenience following a single earth fault (Regulation 314.1).

RCDs (RCCBs, RCBOs AND SRCDs)

l

INSTALLATION TESTING –

CAUTION

l

As Starbreaker and Loadstar RCBOs employ electronic components they

should be disconnected when carrying out the following tests on the electrical

installation:

(a) Earth fault loop impedance test

The load terminals should be disconnected if it is intended to parallel-out the

unit for test purposes.

It may incur damage if mains potential is maintained on the load terminals of

this unit after the trip mechanism has operated.

(b) Insulation test

Whilst RCBOs can withstand the effects of normal insulation testers without

damage, false readings may be given on the test instrument. For this reason

it is recommended that the device is disconnected during this test.

FAULT CURRENT SENSITIVITY

l

Semi-conductor devices are now incorporated in equipment used throughout

industry, commerce and in the home. Typically, the purpose of these semi-

conductor devices is for monitoring and controlling industrial equipment

eg speed controls for small motors and temperature controls, along with

extensive use in computers, VDUs, printers, washing machines, etc.

As the equipment is fed from the mains electrical supply, in the event of an

earth fault the presence of semi-conductors may result in the normal ac

waveform being replaced by a non-sinusoidal fault current. In some cases the

waveform may be rectified or chopped. These waveforms are said to contain

a pulsating dc component which can either partially desensitise or totally

disable a standard Type AC RCD.

International standards IEC 61008 (RCCBs) and IEC 61009 (RCBOs) divide

RCDs into two performance classes:

Type AC

RCDs for which tripping is ensured for residual sinusoidal alternating currents,

whether suddenly applied or slowly arising.

Type A

RCDs for which tripping is ensured for residual sinusoidal alternating currents

and residual pulsating direct currents, whether suddenly applied or slowly arising.

To ensure the correct level of protection, check for the following symbols:

TYPE AC

TYPE A

normal

pulsating

ac sensitivity

dc sensitivity

Crabtree RCCBs are available as both Type AC and Type A devices.

IEC PUBLICATION (60479) CURVES WITH CRABTREE RCD CHARACTERISTICS SUPERIMPOSED

l

TIME/CURRENT ZONES OF EFFECTS OF AC CURRENT (15–100Hz) ON PERSONS

Zone Physiological effects

1

Usually no reaction

4

In addition to the effects

effects.

of zone 3, probability of

ventricular fibrillation

2

Usually no harmful

increased up to 5%

physiological effects.

(Curve C2) up to 50%

(Curve C3) and above

3

Usually no organic

50% beyond Curve C3.

damage to be expected.

Increasing with magnitude

Likelihood of muscular

and time, pathyphysio-

contraction and difficulty

logical effects such as

of breathing, reversible

cardiac arrest, breathing

disturbances of formation

arrest and heavy burns

and conduction of

may occur.

impulses in the heart, and

transient cardiac arrest

without ventricular

fibrillation increases with

current magnitude and

time.

10,000

5,000

2000

1000

500

200

100

50

20

10

0.1 0.2 0.3 0.5 1 2 3 5 10 20 30 50 100 200 300 500 1,000 2,000

10,000

5,000

3,000

Current in milliamperes (RMS)

100mA

30mA

Typical current

Limits due to body resistance

at 230V

1

2

3

4

a

b

c

1

c

2

c

3

IEC 60479

Time in milliseconds

Technical Specifications (RCBOs)

up to 50A

Standards

EN 61009-1, IEC 61009-1

Approved acc.to

IEC/EN 61543

Rated voltages

Un

V AC

230(240)

Rated frequency

fn

Hz

50 ... 60

Rated currents

In

A

6, 10, 16, 20, 32, 40, 50

Rated residual currents

I

D

n

mA

30

Rated switching capacity

kA

6

Energy limitation class

3

Terminals /conductor cross-sections

Solid and stranded

mm

2

0.75 ... 35

Finely stranded, with end sleeve

mm

2

0.75 ... 25

Outgoing

mm

2

0.75 ... 16

Terminal tightening torque

Nm

2

Mains connection

Bottom

Mounting position

Any

Degree of protection acc. to EN60529

IP20 with connected conductors

Touch protection acc. to EN50274

Finger and back-of-hand safe

Service life

Test cycle acc.

switching

.

10000 actuations

to IEC/EN 61009 cycles

Storage temperature

˚C

-40 ...+45

Ambient temperature

˚C

-25 ...+45

Resistance to climate acc. to IEC60068-2-30

28 cycles (55˚C; 95% rel. air humidity

CFC and silicone free

Yes