GE GFK-0787B user manual GE Catalog Number CR7RBXXEL Spectra 700 IEC Control Relay

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commanded state. If it does not, the point is pulsed Off again for about 7.5mS. A maximum of two pulses of approximately 5mS and 7.5mS duration can occur. The 7.5mS pulse occurs only if the volts feedback for the first pulse is incorrect.

Each output device's characteristics should be checked against the list above to verify that it can be autotested and/or used in the 4-block output group. Often, in cases where a desired output device does not by itself meet a requirement, external components can be added to change its characteristics and allow it to operate in a 4-block output group and be autotested. Or, a diagnostic feature (such as autotest, No Load, or Overload) can be disabled to allow it to operate in a 4-block output group. The following are two examples.

GE Catalog Number CR120BDXXX48 Series A 600±Volt Industrial Relay

XXX represents a 3-digit number identifying the type and number of contacts.

This relay has a NEMA A600 rating: Maximum AC Voltage = 600

Maximum continuous current: = 10A

The 24 VDC coil typically draws 117 milliamps at 24 VDC when the relay is picked up. This meets the GMR requirement of a minimum of 100 milliamps to be able to use the No Load diagnostic without using additional external components to increase the load. However, the 24 VDC coil is a dual winding type which draws a higher current during the first part of the armature stroke. Its inrush current is approximately 9.8 Amps at

24VDC, which causes an Overload diagnostic (overload=more than 2.8 Amps) to be generated by the Genius output circuits. To overcome the high inrush current, the Overload diagnostic must be set to NO for those outputs that would be wired to this type or relay. This relay, with no external components, does not exhibit any chatter during the output autotesting, although a flyback diode is still recommended to reduce noise on the 24VDC power lines.

GE Catalog Number CR7RBXXEL Spectra 700 IEC Control Relay

XX represents a 2-digit number identifying the type and number of contacts.

This relay has a NEMA A600 rating: Maximum AC Voltage = 600

Maximum continuous current: = 10 A

The 24 VDC coil typically draws 230 milliamps at 24 VDC when the relay is picked up. This also meets the GMR requirement of a minimum of 100 milliamps to be able to use the No Load diagnostic without using additional external components to increase the load. The inrush current for this relay is low enough that the Overload can be left enabled. However, this relay, with no external components, does exhibit very minor chatter during the output autotesting, although its contacts do not begin to open. A flyback diode wired across the coil eliminates all the chatter and is also recommended to reduce noise on the 24VDC power lines.

GFK-0787B Chapter 8 Installation Information 8-13