Positively Guided Safety Relays

Positively guided (forced guided) safety relay ranges from manufacturer Dold are designed with a mechanical interlock between contacts. This guarantees that all contacts switch together or not at all (for example, if one contact set has welded due to external overload) - hence the designation forced guided relay. The range is available in a variety of upright and flat pack designs, offering from 2 to 8 contact sets.

This requirement is essential for all safety critical and signalling applications where related circuits must operate in tandem. For example, imagine a machine door interlock safety system, contact A drives a motor running in a guarded cage, contact B operates a solenoid that locks the door of the cage. In the event contact A welded, it would be essential that contact B could not switch (thereby unlocking the cage whilst the motor was still running).

Dold positively guided relay devices utilize a force guided contact mechanism (also known as captive, locked or forcibly guided contacts).

Forced guided contacts are mechanically linked so that when the relay coil is energised or de-energised, all the linked contacts move together so that it is impossible for the N/O (normally open) and N/C (normally closed) contacts to be closed at the same time ensuring that if one set of contacts becomes immobilised, no other set of contacts, of the same safety relay, will be able to move. An open contact gap of > 0.5mm is maintained throughout the life of the safety relay, even with malfunction, and at 1.6 x nominal voltage.

Forcibly Guided Relays are the core components for safety devices and circuits to protect as a mandatory requirement of the European Machinery Directive EMD 89/392 EEC and OSHACFR 1910 "General Requirements for All Machinery" (USA).


Certifications
This range is approved for use in safety applications to:
IEC60204/EN60204/DIN-VDE0113/Escalator standard EN115/06.95
Lift (elevator) standard EN81 Part 1.10.86 TRA 101/07.80


Typical Applications for positively guided relays
- Emergency stop safety modules
- DIN Rail safety relay modules
- Safety door controls
- Two-hand operating devices
- Pressure mat controls
- Light barriers and curtains
- Speed controls
- Monitoring devices
- Railway signalling controls

Please note that when selecting forced guided relays it is the responsibility of the user to determine the suitability of a safety relay for the intended application and to determine that the safety relay chosen, and its installation, will comply with all applicable health and safety regulations and codes.

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- acc. to EN 50 205, IEC 255, IEC 664 VDE 0106
- contact opening > 0,5 mm for the whole life, as well as with malfunction and with 1,6 UN
- clearance and creepage distances, coil and contact ³ 8 mm
- high voltage resistance > 4 kV
- high switching reliability due to crown contacts
- small height 39,5 mm
- wide temperature range: at OA 5601 and 5602: - 25... + 85 °C; at OA 5603: - 25 ... + 75 °C
- high continuous thermal current Ith=10A
- mechanical service life
- high voltage range 0,7 UN ... 1,6 UN
- double and reinforced insulation between contact sets according to EN 50 178
- approvals: TÜV, UL, CSA

- according to EN 50 205, IEC 255, IEC 664
- low rated power consumption
- high mechanical service life
- high switching reliability due to crown contacts with large relative movement
- compact size
- Approvals: TÜV, UL, CSA

- according to EN 50 205, IEC/EN 60 255,
  IEC 60 664
- low rated power consumption
- clearance and creepage distances ³ 5,5 mm; d.h. double and reinforced insulation between all circuits
- high mechanical service life
- high temperature range
- high thermal continuous current
- extremely flat: only 15,5 mm high
- Approvals: TÜV (UL, CSA presumed)
- Version with double contacts possible,
- AgNi 0,15 + 5 mm Au-contacts

- according to EN 50 205, IEC 255, IEC 664
- with positively driven contacts
- Clearance and creepage distances, contact-coil ³ 8 mm
- low rated power consumption
- high mechanical service life
- compact size, small height
- Approvals: TÜV, UL, CSA

- according to EN 50 205, IEC 255, IEC 664
- with positively driven contacts
- wash proof model OW as option
- double and reinforced insulation between contact sets according to EN 50 178
- low rated power consumption
- high mechanical service life
- compact size, small height
- Approvals: TÜV, UL, CSA

- according to EN 50 205, EN 60 255, IEC 664
- with positively driven contacts
- wash proof model OW as option
- double and reinforced insulation between contact sets according to EN 50 178
- high dielectric strength
- high mechanical service life
- high switching reliability
- compact size
- high thermal continuous current
- high voltage range
- Approval: TÜV, UL, CSA obtained

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