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A21REL-12 4-Channel Relay Driver
Services Available
Repair No
Free Support Yes

Overview

The A21REL-12 contains four internal relays that allow a Campbell Scientific datalogger to control up to four external ac or dc devices.

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Technical Description

The A21REL-12's internal relays are single-pole double-throw. This relay driver may be powered by the datalogger power supply or a separate 12 Vdc battery.

Specifications

Function Allows a data logger to control up to four external ac or dc devices.
Number of Channels 4
Contact Ratings
  • 1 A (at 20 Vdc)
  • 0.3 A (at 120 Vac)
Coil Current 13 mA/relay
Relays dual single-pole, double-throw relays
Operating Temperature -25° to +50°C
Operating Voltage 12 Vdc
Dimensions 14.0 x 6.9 x 3.0 cm (5.5 x 2.7 x 1.2 in.)
Weight 227 g (8 oz)

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Dataloggers

Product Compatible Note
21X (retired)
CR10 (retired)
CR1000 (retired)
CR10X (retired)
CR200X (retired)
CR211X (retired)
CR216X (retired)
CR23X (retired)
CR300
CR3000 (retired)
CR310
CR350
CR500 (retired) The CR500 has only one control port capable of providing a control signal.
CR5000 (retired)
CR510 (retired) The CR510 has only one control port capable of providing a control signal.
CR800 (retired)
CR850 (retired)
CR9000 (retired)
CR9000X (retired)

Mounting Equipment

Product Compatible Note
ENC10/12
ENC12/14
ENC14/16

Miscellaneous

Product Compatible Note
ENC10/12R
ENC16/18

Additional Compatibility Information

Data Logger Considerations

Each of the four relays is controlled by a data logger control port.

Cables

Cable(s) Used Number of Relays Controlled
One CABLE3CBL-L 1
One CABLE4CBL-L 2
One CABLE5CBL-L 3
Two CABLE3CBL-L 4

Power Considerations

The A21REL-12 may be powered by the data logger power supply or a separate 12 Vdc battery.

Enclosure Considerations

The A21REL-12 requires a non-condensing environment. No mounting bracket is available. The peripheral is typically mounted in the data logger enclosure with double-sided tape or Velcro.

Related Documents


Related FAQs

Number of FAQs related to A21REL-12: 1

  1. The following relay devices can be used with the CR800 and the CR850:

    • 7321
    • A6REL-12*
    • A21REL-12
    • LR4
    • SDM-CD8S
    • SDM-CD16AC
    • SDM-CD16S

    The CR800 and the CR850 can also be used with a wide variety of third-party relay devices.

    *Because the CR800 and the CR850 only have four control ports, they do not have the ability to switch all six of the relays on the A6REL-12.

Case Studies

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