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 |
|
| 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 |
|---|---|---|
| CR1000 (retired) | ||
| CR200X (retired) | ||
| CR216X (retired) | ||
| CR300 | ||
| CR3000 | ||
| CR310 | ||
| CR350 | ||
| CR5000 (retired) | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR9000X (retired) |
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.
Resources and Links
Manuals
FAQs for
Number of FAQs related to A21REL-12: 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-CD16ACA
- 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 digital ports, they do not have the ability to switch all six of the relays on the A6REL-12.
Case Studies
The past few years have seen a scramble within the power industry to use more......read more
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