Photo of a trapdoor with hinged door

How To Automate Your Trap Door Application

Yarina Li
Yarina Li
PA Engineer

A trapdoor is a sliding or hinged door, flush with the surface of a floor, roof, or ceiling, or in the stage of a theatre. A trap door to a basement in a house is a common use. To make a trap door is the easy part. The problem is that it can be heavy and hard to open especially for elders and kids. However, you can automate a trapdoor by mounting a linear actuator on the trapdoor so that it can open and close with just a press of a button. You can choose to use one linear actuator or two linear actuators to open the door. In this blog, we will discuss the control system when using either one actuator or two linear actuators.

 

Should I Use One or Two Linear Actuators for a Basement Trap Door?

An actuator for a trap door

 

When deciding to actuate a trap door, there are a few things that will determine whether you should use one or two linear actuators. The four main factors will be the weight of the door, the type of hinge mechanism used, the number of doors to open, and the available space.

You may also want to refer to another blog on how to calculate the force applied to the actuator.

 

One Linear Actuator

Using one linear actuator for a trap door lift is ideal when you have a trap door that is hinged on one side, much like a regular house door. However, take into consideration the weight of the door and the size of the linear actuator accordingly. If the trap door is too heavy, opting for two linear actuators may be your next best option.

To open the door with just one linear actuator, the control system is really simple. All you need is a 1-channel control box that can provide sufficient current and voltage. Our PA-31 and PA-33 wireless control box will be enough to control all of our 12VDC actuators. You may also control the linear actuator with a rocker switch. If you are going to power the linear actuator from the wall outlet, you would need to have a power supply to convert from 110VAC to 12VDC.

The actuator can also be controlled by a rocker switch. When you are selecting the rocker switch, please make sure that it can pass enough current to the actuator. The current rating of the rocker switch must be greater than the current rating of the linear actuator. You may refer to the wiring diagram for more information on the rocker switch.

 

Two Linear Actuators

Using two linear actuators for a trap door lift is ideal when one linear actuator could not provide enough force to push the weight of the trap door open and closed.

To open the door with two linear actuators, we would recommend using the linear actuator with a Hall-Effect sensor. The reason for that is the linear actuator would have a speed tolerance of ± 10% without the Hall-Effect Sensor. With the Hall-Effect Sensor being added, the linear actuator would have a travel difference of ±3mm. Our in-stock units with Hall-Effect Sensor would be the PA-04-HS. If PA-04-HS is not going to work for you, we can customize the majority of our units with the Hall-Effect Sensor. Please note the lead time would be 20-25 days for a custom order and custom sales are final.

 

Control Systems for a Hall-Effect Sensor Actuator

Photo of a control system for Hall Effect sensor actuator 

We have two control systems that are going to be used for the Hall-Effect Sensor linear actuator to automate the basement trap door opener, namely, a 12VDC and 24VDC control system.

 

12 VDC Control System

To control the linear actuator with a 12VDC control box, the first thing you need to make sure is the linear actuator is rated for 12VDC. The 12VDC control box we have is PA-40 and it comes with a wireless remote. If you are looking for wired control, you can purchase the RC-13, which is a small rocker switch that can directly plug into the control box. The PA-40 would have an input voltage of 12VDC and an output of 12VDC as well. If you are going to plug it into the wall outlet, you would need to get the power supply. The voltage must be 12VDC and the current rating must be greater than the total current of the two linear actuators.

 

24 VDC Control System

To control the linear actuator with a 24VDC control box, you must make sure you choose a linear actuator with 24VDC. The 24VDC control box we have is the FLTCON control box and it does not come with a remote, you would need to purchase a hand remote separately. The FLTCON control box will have an input voltage of 110VAC and an output voltage of 24VDC. You can directly plug the control box into the wall outlet.

 

Conclusion

This article should have given you a good idea as to when to use one or two linear actuators when automating a mechanical trap door to a basement. Moreover, you should now know how to pair a linear actuator with a Progressive Automations control system. For more information on the mentioned products, visit our website. Alternatively, if you have any questions about selecting the linear actuator or control box for your application, please give us a call at 1-800-676-6123 or email us at sales@progressiveautomations.com.