RSS Solid State Relay

The "hockey puck" style RSS series of solid state relays allow switching of the most demanding loads. Highly resistant to inrush, with a built-in snubber, the RSS series is ideal for switching loads such as lights and heaters. Available with either DC (4-32V) or AC (90-280V) inputs and?output current ratings up to 90A.?All models feature zero-voltage turn-on to reduce inrush current and a dual SCR switch (rather than a triac) for enhanced reliability and superior heat dissipation properties.

Key Features:

• Current ratings up to 90A at 660VAC
• AC (90-280V) or DC (4-32V) input
• Input current regulated 10mA
• Photo isolation of input and output (up to 4000V)
• Zero voltage turn on
• Dual SCR output with built-in snubber
• Optional fingersafe cover
• Worldwide approvals: UL, C-UL, TUV, CE
• LED status indicator standard
• Updated pressure plate for easier installation of wires
• New housing design keeps wires from twisting and breaking
• Dual SCR output with epoxy free design

Need samples to test? Contact us at?sales@xtronics.ca

Relays! What are they and how do they work

The basics. Relays are switches that open and close circuits electronically and electromagnetically. They are electric switches that use electromagnetism to convert smaller electrical current into larger currents.

Relays are typically used in control panels, manufacturing, and building automation to control the power along with switching the smaller current values in a controlled circuit.?Relays have an amplifying effect and can manage larger voltages because a small voltage applied to a relays coil can result in a large voltage being switched by the contacts.

By leveraging weak inputs to power stronger currents, relays effectively act as either a switch or an amplifier for the electric circuit, depending on the desired application. Relays ensure complete circuitry isolation between the controlled and the controlling circuits.

Relays also protect your equipment by detecting and preventing damaging electrical abnormalities such as under and over current, overload, or reverse current. Relays are usually confined to smaller motors and and solenoids that draw low amperes, but additionally used for audible alarms, heating elements, pilot lights and to switch starting coils, etc.

Components of an electromechanical relay.

Basic mechanical relays are comprised of 2 main circuits - the primary circuit and the secondary circuit. The primary circuit provides the control signal to operate the relay and enable the contacts on the other circuit. This could be controlled by a mechanical switch, thermostat or some other type of sensor. As mentioned above the primary circuit is typically connected to a low voltage DC supply, enabling a higher voltage supply. The secondary circuit is the is the circuit that contains the load to be controlled, whether it be a fan, pump or compressor.

On the primary side we find an electromagnetic coil that that generates an electromagnetic field when current runs through it. At the end of the electromagnet can be found the armature, a small pivoting lever with a contactor, that when energized pulls the lever down to the contact enabling current to flow. A small spring is also used to disengage the connection when the magnet is turned off.

There are two types of relays: NO - Normally Open; and NC - Normally Closed. As you can guess NC works the opposite of an NO relay.

SSR - Solid State Relays

There are more then just electromechanical relays on the market, each with different operation principals and with different polarities. Take solid state relays for example. Due to the fact that it has no moving parts it has a much longer lifetime then other relays.

Solid Sate Relays use electrical and optical properties of solid state semiconductors to perform its input and output isolation as well switching functions. On this device we see an LED light instead of electromagnets on the primary side. The LED within a solid state relay provides optical coupling by shining a beam of light across a gap into a receiving and adjacent photo sensitive transistor located on the secondary circuit side. This relay operation is controlled by simply turning on and off the LED.

The phototransistor acts as an insulator and does not allow current to flow until its exposed to light. Inside a phototransistor there are different layers of semiconductor materials: N-type and P-type that are sandwiched together.

The photons emitted by the LED push the electrons from the first barrier of the n-type to the p-type then on to the n-type material completing the circuit thus allowing control of the secondary circuit just by using a beam of light.

As stated there are many different types of relays, from NO controlling the secondary circuit with a bimetallic strip on the primary side , to NC to control a single pump system maintaining a desired liquid level. Sometimes we want the secondary circuit to remain live while the primary circuit remains live: example a latching relay of an elevator button. Latching relays provide positional memory and once activated will remain in last position without the requirement for any other input of current.

As a trusted distributor of IDEC we provide the entire IDEC Switches and Relays lineup and more; IDEC RH Series?- SPDT through 4PDT plug In or PCB type, 10A contacts. The RR Series - Rugged 10A Octal classic relays, DPDT and 3PDT plug in type. The RSC Series -?Solid State Relay with built in heat sink, AC Switching loads from 20A to 45A. The RSS series as stated above - Hockey Puck Solid State Relay, AC switching loads from 10A to 90A. RY2KS Latching Relay - Contacts rated 3A/240V AC, 3A/30V DC

Reach out to us with any questions you may have! sales@xtronics.ca

Sources: us.idec.com/idec-us/en/USD/Relays, TheEngineeringMindset.com, galco.com/comp/prod/relay