C9-R21N/DC60V

Q: What is a latching relay and when is it used?

A latching relay is a bistable relay that retains its switching state even if the supply voltage is interrupted. This means that the last selected switching position - whether switched on or off - remains reliably stored until the relay is deliberately switched over.A latching relay is used wherever the switching status must be retained after a power failure or interruption. This means that installations or systems can continue to operate safely and stably after an interruption without having to reset the status.The most important advantages include high energy efficiency and operational reliability. Energy is only required during the changeover, but not to maintain the status. At the same time, the ability to maintain the switching state even in the event of a loss of voltage provides additional reliability and protection against unwanted changes in operation.

Q: May both control inputs of a latching relay be activated at the same time?

For latching relays with DC coils, both control inputs can be supplied simultaneously. In this case, control input A1 (ON) always takes precedence over control input A3 (OFF).The situation is different for AC coils: If both control inputs are energized simultaneously, this leads to uncontrolled toggling of the contacts. As a result, the relay is destroyed within a very short time. For this reason, both control inputs must never be activated simultaneously for latching relays with AC coils.

- 2 pole
- Changeover contacts / Remanence
- Contact material AgNi + 0.2 µm Au
- Max 5 A @ 120 V AC / 30 V DC

Nominal voltage	60 V
Current type	DC

Pick-up voltage	≤ 0.8 U_N
OFF pulse power	0.2 VA / 0.3 W
Operating voltage range	0.8 U_N … 1.1 U_N
ON pulse power	AC 1.2 VA, DC 1.2 W
Release voltage	≤ 0.8 U_N

Housing material	PA / PC
Maximum switching frequency at rated load	1 200 / h
Minimum pulse length ON / OFF	50
Operation temperature	-40 … 60 °C
Storage temperature (no ice)	-40 … 80 °C
Weight	43 g

Insulation resistance at 500 V	≥ 1 GΩ
Overvoltage category	III
Pollution degree	3
Test voltage contact / coil	2 kV / 1 min
Test voltage contact / contact	2 kV / 1 min
Test voltage open contact	1 kV / 1 min

Contact materials	AgNi + 0.2 μ Au
Electrical endurance at rated load AC-1 (cycles)	≥ 100 000
Inrush current	15 A, 20 ms
Maximum contact load AC-1	5 A / 120 V AC-1
Maximum contact load DC-1	5 A / 30 V DC-1
Mechanical endurance (cycles)	≥ 10 000 000
Number of contacts	2 CO
Rated current	5 A
Rated load AC	600 VA
Recommended minimum contact load	10 mA / 10 V

Approvals	UKCA,CE,EAC,cURus,CSA
Standards	IEC/EN 61810,IEC/EN 60947

Approvals

Data sheet

3D-models "C9-R21N/DC60V"

C9-R21N/DC60V / STEP file

Remanenzrelais

What is a latching relay and when is it used?

A latching relay is a bistable relay that retains its switching state even if the supply voltage is interrupted. This means that the last selected switching position - whether switched on or off - remains reliably stored until the relay is deliberately switched over.

A latching relay is used wherever the switching status must be retained after a power failure or interruption. This means that installations or systems can continue to operate safely and stably after an interruption without having to reset the status.

The most important advantages include high energy efficiency and operational reliability. Energy is only required during the changeover, but not to maintain the status. At the same time, the ability to maintain the switching state even in the event of a loss of voltage provides additional reliability and protection against unwanted changes in operation.

How does a remanence relay work?

A remanence relay works through magnetic remanence: when the relay is switched, residual magnetism remains in the magnetic core, which keeps the armature in its position even if the supply voltage is switched off. The switching state is therefore stored stably until a new control signal generates an opposite magnetic field that compensates for the existing residual magnetism. Only then is the relay deliberately switched into the new state. In this way, it only requires energy during the switching process and combines high efficiency with operational reliability.

How do I find a latching relay?

Latching (remanence) versions are available for our industrial relay series C3, C4, C5 and C9. In the product code, they are identified by the letter R in the 3rd position: C3-R*, C4-R*, C5-R*, C9-R*.

In the railway sector, we offer latching versions for the R3-R.

May both control inputs of a latching relay be activated at the same time?

For latching relays with DC coils, both control inputs can be supplied simultaneously. In this case, control input A1 (ON) always takes precedence over control input A3 (OFF).

The situation is different for AC coils: If both control inputs are energized simultaneously, this leads to uncontrolled toggling of the contacts. As a result, the relay is destroyed within a very short time. For this reason, both control inputs must never be activated simultaneously for latching relays with AC coils.