Door interlock system for shutters and doors to open one at a time

In pharmaceutical warehouses and food warehouses, we provide modification of the shutter interlock system for temperature and humidity control. In Middle East countries, management of temperature and humidity is a challenge for cold chain segments. In order to limit the inflow of air from the outside environment, many measures are taken.

If you have two sets of doors or shutters and you may want to control the opening. You may want to prevent the opening of two doors or shutters simultaneously. In such cases, you can use our shutter interlock system. It can either block the second door from opening or generate an alert.

Door interlocking system by modification of existing shutters of warehouses

Normally there will be two sets of doors in the loading and unloading area. One set will be opening to the outdoor where the van or trucks are docked to load the goods. The second layer will be to the indoor area and there will be a space between these two layers of doors. A typical arrangement will be as shown in this drawing.

In order to limit the flow of external air into the warehouse, it is ideal to control the opening of the doors. This can be achieved through different means. We provide different types of the shutter interlock system.

• Shutter interlock system preventing simultaneous opening of rolling shutter doors

As mentioned earlier, there are two layers of doors. If any of the doors of one layer is opened, it should not be possible to open many shutter doors of the other layer. As an example, in the drawing shown above, if door 5 is opened, it should not be possible to open any of the shutters on the opposite side ie. Door 1,2,3 or 4. Similarly, if door 2 is opened first, the door 5,6 or 7 cannot be opened. This is a door interlock system. This will prevent the simultaneous opening of shutters. If you are using the same for shutter we provide a slightly different shutter interlock system.

We will explain through an operational example. Suppose a van is waiting at Door 5 for loading. Now all the doors are closed. First, open any of the door nos. from 1 to 4. eg. Open the door 1 and bring the medicine boxes to the space between the doors in a forklift. Now close the door 1 and thereafter open door 5. Now load the goods to the van. Thereafter close door 5 and open door 1 and the forklift can return to the warehouse.

The customer can open all the doors of one side simultaneously. eg. we can open Door 1,2,3 & 4 simultaneously. Similarly, Door 5,6 & 7 can be opened together. However, if anyone door on one side is opened, the doors on the other side cannot be opened.

For rolling shutters, the control circuit will be provided through the motor. So only one motor can be activated at a time or as programmed. Even if you have door control systems such as Crawford (®), we can still provide the shutter interlock control system.

Also if you want to limit the simultaneous opening of doors on any one side this can be achieved. eg. if you want to limit so that only 2 doors should be opened together this can be achieved. So if Door 1 and 3 are opened, the customer cannot open door 2 and 4 and so on.

• Door interlock system for glass or wooden swing/sliding doors

  For normal swing or sliding doors, the control panels will be the same. However, we will be using the magnetic door latches for interlock. The magnetic lock will remain activated facilitating the opening of only one door at a time or as programmed. Other functions will be the same. We can provide a bypass key to deactivate if required. We will use different types of sensors for these types of doors. Thus the system will prevent the simultaneous opening of doors.

• Siren system to alert simultaneous door or shutter opening

If you do not want a door interlock system, you can provide a warning system. In this case, if anybody opens doors on opposite sides, there will be an audible alarm. This is mainly to alert the operators especially when you have a huge warehouse. In this system, any number of doors can be opened simultaneously. But the operator will be aware that doors on opposite sides are opened and they should close one of them as quickly as possible. This will prevent the simultaneous opening of doors or shutters.

We are supplying these door interlocking systems and shutter interlock systems for pharmaceutical storage warehouses, food storage warehouses etc. where temperature and humidity control is essential.

Also, see our previous article on door automation with the automation of air curtains