relays 178 Scan for pricing or go to www.delcity.net/ catalogpricing www.delcity.net email@example.com Change over relays are used in applications that require Change Over Relays, Normally Open Relays or Normally Closed Relays. INFORMATION Change Over Relays Change Over Relay Wiring OPERATING CHARACTERISTICS: Permissible ambient temperature = -40°C to 125°C (-40°F to 257°F) Mechanical Life–no load = 10,000,000 operations (frequency 18,000 operations/hr) The following applies for all relays unless otherwise noted: - Operating voltage = 8–16V at 12V; 16–32V at 24V - Contact voltage drop(1) = Typ. 50MV at 10A - Insulation resistance(1) = 20MΩ Min. (DC 500V) - Operate time(1) = 20ms Max. - Release time(1) = 20ms Max. - Resistive load N.O. = 50A at 14V DC - Resistive load N.C. = 30A at 14V DC - Dielectric strength N.O.(1) = AC 500V, 50/60Hz 1 min - Dielectric strength N.C.(1) = AC 500V, 50/60Hz 1 min - Life Expectancy Mechanical = 10,000,000 operations (frequency 18,000 operations/hr) - Life Expectancy Electrical = 100,000 operations (frequency 1,200 operations/hr) A change over relay switches current from one user to another. Change over relays are used for switching from one horn to the fan, from forward to backward movement of the sliding roof, from opening to closing electrically operated windows and for two-stage uses such as fans and some rear window heating systems. 87a 87 85 86 30 87a 87 85 86 30 87a 87 85 accessory accessory ground battery 86 30 Inside A Relay If we were to open a standard relay, you would see an electromagnet coil, the contacts, and a spring. The spring holds the contact in position until a current gets passed through the coil. The coil then generates the magnetic field which moves the contact on and off. Pin Labels On A Relay This is a diagram of a typical 12V relay. Each pin is numbered. 85 and 86 are the coil pins while 30, 87, and 87a are the contact pins. Pin 87 and 87a are the two contacts to which 30 will connect. If the coil is not activated, 30 will always be connected to 87a. You can think of this as the switch in OFF. When current is applied to the coil, 30 is then connected to pin 87. You can wire relays to be either open or closed, depending on how you need your accessory to operate. If you want a normally closed relay, you will want to wire to 87a. If you want a normally open relay, you will wire to 87. Although most relays are labeled at the bottom, you can always find the 30 pin set perpendicular to pins 87 and 87a for easy identification to the power source. Output For A Relay Pin 85 and 86 are the coil pins and will be transferring the current through the coil. Pin 85 will be used to ground your relay, while 86 will be connected to the switchable power. Pin 87 and 87a will be connected to your controlled accessories that you wish to turn on and off with your relay. Pin 30 will then be the pin connected to your battery power.