The Schrack V23050 series relay, also known as the SR6, from TE Connectivity has forcibly-guided contacts to help minimize switching issues. A product such as this is sometimes referred to as a “safety relay.” It is designed such that its “make” and “break” contacts cannot be simultaneously in the closed position, even in the event of a major malfunction such as contacts welding or a contact spring breaking.
Primary applications that might require the SR6’s capabilities include elevator and escalator control systems. Other applications include “emergency stop” controls, light (photoelectric) curtains and safety controls for industrial machinery such as presses and saws.
The design isolates each of the SR6’s six contact sets within its own individual contact chamber. Users may choose from models with four normally open (NO) and two normally closed (NC) contacts, two NO and four NC contacts or five NO and one NC contact. The silver tin oxide contacts are rated for 8 amp loads at 250 volts AC.
At 2.165 x .65 x .63 inches tall (55 x 16.5 x 16 mm), the PC board mount SR6 is significantly more compact than previous designs; however, it still offers excellent dielectric withstand characteristics. Surge resistance between poles is 6kV. Both clearance and creepage distances are 5.5 millimeters from coil-to-contacts and between adjacent contacts.
Standard SR6 relays are offered with coils for 5 – 110 volts DC and require 1200 milliwatts of coil power. A sensitive version, the SR6S, is offered with polarized coils for 5 – 48 volts DC and requires one-third less coil power at just 800 milliwatts.