How to size the cam lock and latch you need
The cam lock latch is often an important cabinet latch hardware requirement. While many enclosures are secured by simple tab style latches, those where access is regularly needed use cam locks and latches.
What is a cam lock?
Cam locks, or cam locking systems, as they are also known, are locking levers that are used across a range of applications. Often used in cabinet construction, they are widely used to secure doors and enclosures such as:
- Data rack enclosure cabinets
- Datacentre server cabinet
- Outdoor telecoms equipment or utility cabinet
- Outdoor weatherproof electrical enclosures
- Electrical cable enclosures on industrial machinery
- HVAC system components enclosures
How to size a cam lock
When choosing the correct cam lock or latch, you'll need to match the IP or NEMA rating of the enclosure. Two examples are NEMA 4x electrical enclosures (washdown duty rating) and the NEMA 3R electrical enclosure designation (rain tight, dust proof). The latch rating must match so that the enclosure is not de-rated.
When you are choosing a cam lock, ensure you size it correctly for a snug and secure fit.
Housing Height
A hinged electrical junction box or equipment enclosure door will normally mate with the surface of the cabinet or enclosure, often sealing over a vertical lip. However, some enclosures are made with recessed doors, making contact with an inner lip built into the box. In either case, this is one of the first dimensions you need to properly size the cam lock:
- Determine the distance between the outer surface of the door and the inner surface of the enclosure where the cam will make contact. This will determine the housing height, also called the barrel length.
|
Dimension Sizing Example |
|
|
Dimension To Be Measured |
Example Dimension |
| Grip Range | 1.063 - 2.835 in |
| Head Height | 0.984 in |
| Housing Height | 1.26 in |
| Maximum Compression | 0.236 in |
| Maximum Grip | 2.835 in |
| Maximum Panel Thickness | 0.709 in |
| Minimum Grip | 1.063 in |
Maximum Panel Thickness
The actual thickness of the door is not usually an issue in metal enclosure because the barrel of the latch is threaded and secured with a locking nut. However, the maximum panel thickness may be important if the door is made of wood or other thick materials.
Grip Range
In the above example, you see the grip range dimensions. Often this is adjustable, and its main purpose is to allow for the gasket used (if any) to seal the door. Note that the grip range has a maximum and minimum grip dimension.
Maximum Compression
Maximum compression also plays into the snugness of the door to the enclosure’s fit.
The barrel or housing must be matched to the latch hole in pre-punched doors. Most barrels are round and have a threaded diameter to accept the locking nut but are also flat on opposing sides to prevent the latch from turning in the mounting hole.
Head Height
In the dimension sizing example above, the head height is the least important.
Other cam lock considerations
Often the compression can be adjusted when the door is closed by rotating the latch knob. This type of design makes it easier to close the latch and then tighten the seal.
Handles for cam locks come in a variety of configurations:
- L-handles
- T-handles
- Lift and turn latches, both keyed and non-keyed
- Wing knob compression latches
- Padlock enabled latches
The configuration you choose is determined by how often the enclosure is accessed, how secure you need the enclosure to be (e.g., authorised personnel only), and whether you need a low-profile latch to prevent damage from personnel traffic.
You may need to specify a lockable latch, often a keyed one. However, you can use a tamper resistant latch that requires a special tool to open it.
Low profile lift and latch cam locks will add another dimension to consider. Doors that accept these latches will have a rectangular hole cut or punched into them instead of the rounded hole. Take that dimension as well when choosing or specifying your electrical enclosure locks and latches.
Download free CADs and try before you buy
Free CADs are available for most solutions, which you can download. You can also request free samples to make sure you’ve chosen exactly what you need. If you’re not quite sure which solution will work best for your application, our experts are always happy to advise you.
Whatever your requirements, you can depend on fast despatch. Request your free samples or download free CADs now.
Questions?
Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.