Relay Standards and Operating Conditions
According to which standards are relays manufactured and what needs to be considered regarding installation position, voltage peaks and control? An overview.
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According to which standards are relays manufactured?
Unless expressly stated otherwise, the relays we supply are manufactured in accordance with the following international and European regulations:
- EN 61810-1, -2, -7 for switching relays
- EN 50205 for relays with forcibly guided contacts
- EN 61812-1 / VDE 0435 T2021 for time relays
The specified technical values are based on a reference environment according to EN 61810-1:2004 / VDE 0435 Part 201: 23 °C ambient temperature, 96 kPa air pressure, 50 % relative humidity. The tolerance of coil resistance, rated current and coil power is ± 10 %.
Safe isolation between coil and contact set
Many of our relays offer safe galvanic isolation between the input circuit (coil) and the output circuit (contacts) – important wherever control and load circuits have different voltage levels. This is based in particular on:
- VDE 0106 Part 101 – basic requirements for safe isolation in electrical equipment
- EN 50178 / VDE 0160 – equipment of high-voltage installations with electronic equipment (5.5 mm clearance, 6.4–8 mm creepage distance)
Operating range of the input voltage
The operating range describes the voltage window within which a relay operates reliably over the entire range of its class at the permissible ambient temperature:
- Class 1: 80 % to 110 % of the rated voltage
- Class 2: 85 % to 110 % of the rated voltage
Important notes for practical installation
- Installation position: when using retaining brackets or plastic retaining clips, any position is permitted unless the respective relay series specifies otherwise
- Ambient temperature/condensation: the temperature directly at the relay is decisive, not the room temperature – condensation or ice formation in the relay must be excluded
- Voltage peak limitation: for smaller relay series, a varistor (AC) or diode (DC) circuit is recommended from a coil voltage of 110 V to limit voltage peaks when switching off
- Long control lines / AC proximity switches: capacitive coupling or small residual current values can prevent sensitive relays from releasing safely – a bleeder resistor of approx. 62 kΩ/1 W connected in parallel with the relay coil provides a remedy
Questions about the conditions of your application?
Unsure whether your application requires a special version? Contact us – we will check the technical conditions together with you.
Frequently asked questions
A galvanic isolation between coil (input circuit) and contact set (output circuit), which complies with the clearances and creepage distances as well as dielectric strength defined in standards such as VDE 0106 T101 and EN 50178 – important when control and load circuits have different voltage levels.
Common causes are capacitive coupling on long control lines or residual current from AC proximity switches. A parallel bleeder resistor (approx. 62 kΩ/1 W) across the relay coil usually provides a remedy.