Can this be used on a 24V Hvac system? To shut the system off when the garage door is open?

Voltage would be okay, but you’d be better to use this switch to trigger an SSR as I’m not sure of the current demand of the HVAC system.

Can this be used directly in a 110v circuit with a LED (9w) lamp?

Dry closure contacts can be used in combination with a switching relay to accommodate high voltage applications.

How does this work to advise you the garage door is open?

The circuit is closed when the door is closed. When the door is open, the alarm will trip.

12v circuit in series with switch sensor and a 12v solenoid (60ma) load. Why is the switch closed permantly when activated by magnetic?

It sounds like you are attempting to use this magnetic switch to control an output device, as per the solenoid. The switch would be designed to be used as an input interrupting device to trigger an open circuit on an alarm system. Even though only 60ma draw, it may be too much for the switch to let go of the contacts under draw. Two things you can try. An alarm system would use a 4.7K ohm resistor at the end of the line of a single circuit across the + and - terminals. This would draw down any lingering power in the circuit and possibly release the contact. If you have done that and it is not fixing the error, you could try running the magnetic switch to a small trigger relay, and have the relay switch the solenoid. If you are still unsuccessful, a mechanical limit switch in place of the magnetic trigger switch would be necessary and should solve your issue.

ASIN	B07ZBT28L8
Best Sellers Rank	#152,183 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #44 in Garage Door Sensors
Customer Reviews	4.5 4.5 out of 5 stars (186)
Date First Available	October 20, 2019
Is Discontinued By Manufacturer	No
Item Weight	10.2 ounces
Item model number	MC-55ZL
Manufacturer	GAGALOR
Product Dimensions	4.17 x 1.97 x 0.79 inches

Heavy Duty Wired Alarm Magnetic Garage Door Contact Switch Sensor NC with Adjustable Bracket

Description

Specifications

Common Questions