Contact Design

GRUNER relays meet the required contact gap with one contact only. The impedance and heat loss is much lower compared to designs based on series contacts. With two contacts switched in series, the power consumption and heat generated by the contact current are doubled.

At higher load currents or in applications, where self heating is problematic, GRUNER offers the 722, 733, 740 and 741 type relays. They contain two contacts in parallel to minimize the contact resistance. Some GRUNER relay versions are available with an integrated low impedance shunt. Even with this combination, the power consumption in the current circuits of metering equipment is well below specified limits for metering equipment.

Rotary H-Armature Driving System

The contacts in GRUNER latching relays are driven by the unique Rotary H- Armature driving system. It creates no acceleration forces during operation. Additionally, this system is very robust against shock and vibration applied externally, for example during a tamper attempt.

Small Dimensions and Light Weight

There are limits to what extent a relay can be reduced in size. The dimensions and weights of GRUNER latching relays are optimised to meet the performance requirements of each type. The bus bar connections require a minimum size and area to dissipate heat and to keep the impedance in the current circuit low.

The size of the driving coil is depending on the contact force and distance requirements. The engineers at GRUNER are challenging these limitations with every new relay design.

Well Proven and Optimised Design

GRUNER latching relays are constantly being improved and optimized. Data from the production process, testing and quality assurance at GRUNER, feedback from customers and observations in the field are analyzed and taken into account for the optimization of existing and new relay designs.