A21ACQ24VDC1.9

Relay Automotive Overview

The A21ACQ24VDC1.9 is an automotive relay manufactured by CIT Relay and Switch, designed for high-current switching applications. It features a single-pole single-throw normally open (SPST-NO) contact configuration with a maximum rated current of 40A and a switching voltage up to 75VDC. The coil operates at 24VDC with a power consumption of 1.9W and a resistance of approximately 143 Ohms. Key electrical parameters include a minimum pull-in voltage of 16.8VDC and a minimum release voltage of 1.2VDC. The device offers fast switching times, with an operate time of 7ms and a release time of 5ms. It utilizes silver tin oxide (AgSnO) contacts and supports quick connect terminals measuring 0.250 inches (6.3mm).

Relay Automotive Feature Summary

• High switching capacity capable of handling up to 40A loads in automotive environments.
• Compact design providing small size and light weight for efficient integration.
• Sealed construction ensures reliability against environmental factors.
• Socketable mounting option facilitates easy installation and replacement.

Relay Automotive Applications

• Automotive lighting systems
• Motor control circuits
• Heater and fan controls

Relay Automotive Procurement Notes

Verify the specific suffix '1.9' to confirm the 1.9W coil power rating and corresponding 24VDC coil characteristics. Ensure compatibility with socket bases if socketable mounting is required rather than direct PCB pin mounting. Confirm terminal style matches the 0.250-inch quick connect specification for proper wiring integration.

Relay Automotive Selection Notes

Select this model when a 40A SPST-NO automotive relay is needed for 24VDC systems. Consider the 7ms operate time for applications requiring rapid response. Verify that the operating temperature range of -40°C to +125°C meets the environmental conditions of the target application.

Relay Automotive Part Context

This component belongs to the A2 series of automotive relays from CIT Relay and Switch. The series is characterized by large switching capacities and compact dimensions. Variants within the series differ primarily by coil voltage and power ratings, such as the 12VDC 1.6W version or other 24VDC configurations.

Relay Automotive Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Cross-reference with other CIT A-series relays only if coil voltage and current ratings match exactly.