Q: Which type of RCD should I use and when?

Type A/AC RCDs: Type A and AC RCCBs trip in the event of sinusoidal AC fault currents, type A also in the event of pulsating DC fault currents. These protective devices are primarily used for single-phase loads with electrical components in the power supply unit. Type F RCDs: Single-phase frequency converters are used in many modern appliances, such as washing machines and heating pumps. These appliances can generate fault currents from a frequency mixture with frequency components in the kHz range. RCDs of Type F protect against this and feature an inrush current withstand capacity of >3 kA and a withstand capacity for smooth DC fault currents of up to 10 mA. Type B RCDs: The all-current-sensitive RCDs SENTRON 5SV3 Type B/B+ with an integrated SIGRES function are used for protection against smooth DC fault currents. These devices have an additional transformer that detects DC fault currents separately and are suitable for use in three-phase systems upstream of input circuits with rectifiers.

Q: What versions are available to meet specific requirements?

Patented SIGRES version: Patented SIGRES versions were designed for protection under special conditions. Thanks to the integrated condensation protection, they offer maximum safety and a long service life. Super-resistant K: With an impulse withstand strength greater than 3 kA, unwanted shutdowns are prevented by briefly delaying the triggering of the RCCB. This avoids unnecessary tripping and system disruptions – for example, in the case of pulsed leakage currents when a capacitor is switched on. Selective S: With an impulse withstand strength greater than 5 kA, the selective shutdown of individual system parts is made possible by a tripping delay and a staggering of the tripping time and rated residual current.

Question 1

Which type of RCD should I use and when?

Accepted Answer

Type A/AC RCDs:
Type A and AC RCCBs trip in the event of sinusoidal AC fault currents, type A also in the event of pulsating DC fault currents. These protective devices are primarily used for single-phase loads with electrical components in the power supply unit.
Type F RCDs:
Single-phase frequency converters are used in many modern appliances, such as washing machines and heating pumps. These appliances can generate fault currents from a frequency mixture with frequency components in the kHz range. RCDs of Type F protect against this and feature an inrush current withstand capacity of >3 kA and a withstand capacity for smooth DC fault currents of up to 10 mA.
Type B RCDs:
The all-current-sensitive RCDs SENTRON 5SV3 Type B/B+ with an integrated SIGRES function are used for protection against smooth DC fault currents. These devices have an additional transformer that detects DC fault currents separately and are suitable for use in three-phase systems upstream of input circuits with rectifiers.

Question 2

What versions are available to meet specific requirements?

Accepted Answer

Patented SIGRES version:
Patented SIGRES versions were designed for protection under special conditions. Thanks to the integrated condensation protection, they offer maximum safety and a long service life.
Super-resistant K:
With an impulse withstand strength greater than 3 kA, unwanted shutdowns are prevented by briefly delaying the triggering of the RCCB. This avoids unnecessary tripping and system disruptions – for example, in the case of pulsed leakage currents when a capacitor is switched on.
Selective S:
With an impulse withstand strength greater than 5 kA, the selective shutdown of individual system parts is made possible by a tripping delay and a staggering of the tripping time and rated residual current.

Why SENTRON residual current protective devices?

Key benefits

Protect reliably

Save space

Simplify retrofits

Featured capabilities

Scalable RCD protection for every fault current

RCD protection against smooth DC residual currents

Flexible RCBO functionality with RC units

Complete protection in one device: the RCBO

Multi-pole RCBO protection for complex circuits

Type A and F RCBOs with all-round protection

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