Selection Of Types Of RCD

RCD's ex­ist in vari­ous dif­fer­ent forms and re­act dif­fer­ently de­pend­ing on the pres­ence of DC com­pon­ents or dif­fer­ent fre­quen­cies.

The fol­low­ing RCD's are avail­able with the re­spect­ive sym­bols and the de­signer or in­staller is re­quired to se­lect the ap­pro­pri­ate device for the spe­cific ap­plic­a­tion.


RCD Test­ing

When should Type AC RCD be used?

Gen­eral pur­pose use, RCD can de­tect & re­spond to AC si­nus­oidal wave only.


When should type A RCD be used?

Equip­ment in­cor­por­at­ing elec­tronic com­pon­ents RCD can de­tect & re­spond as for type AC, PLUS pulsat­ing DC com­pon­ents.


When should type F RCD be used?

Equip­ment with fre­quency con­trolled speed drives RCD can de­tect & re­spons as for type A, PLUS high fre­quency re­sid­ual cur­rent.


When should type B RCD be used?

Elec­tric vehicle char­gers, PV sup­plies.

RCD can de­tect & re­spond for type F, PLUS smooth DC re­sid­ual cur­rent.


RCD's & Their Loads


Types of Load       

Type AC                 

Resistive, capacitive, inductive loads
Im­mer­sion heater, oven / hob with res­ist­ive heat­ing ele­ments, elec­tric shower, tung­sten / halo­gen light­ing

Type A

Single phase with electronic components
Single phase in­vert­ers, class 1 IT & mul­ti­me­dia equip­ment, power sup­plies for class 2 equip­ment, ap­pli­ances such as wash­ing ma­chines, light­ing con­trols, in­duc­tion hobs & EV char­ging

Type F

Frequency controlled equipment
Ap­pli­ances con­tain­ing syn­chron­ous mo­tors, some class 1 power tools, some air con­di­tion­ing con­trol­lers us­ing vari­able fre­quency speed drives

Type B

Three phase electronic equipment
In­vert­ers for speed con­trol, ups, EV char­ging where DC fault cur­rent is >6mA, PV




More from the 18th Edition

Surge Protection

A transient overvoltage or surge is a short duration increase in voltage measured between two or more conductors. In short this means anything from microseconds (millionths of a second) to a few milliseconds (thousandths of a second) in duration.

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Arc Fault Detection Devices

Arc fault protection devices (AFDD) use microprocessors to identify characteristic current flow and voltage curves that indicate an arc fault and automatically trip the affected circuit.

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Overload Protection

Devices such as switches, RCCBs etc. in distribution boards and consumer units may have historically had their rated current determined after having taken diversity into account but without having considered overload protection of the devices.

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BEAMA Guides

A collection of the latest guides relating to 18th Edition, Hager is proud to be a technical contributor to these guides which provide technical advice on a range of 18th Edition related topics.

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Related Products

Check out our product solutions for Type A RCDs below.


We have a wide range of RCCBs in Type A.



We have a wide range of RCBOs available in Type A.