Picking the right enclosure for a machine design is extremely important. If you get it right everything is going to last and work great and be easily maintained. If you get it wrong things will overheat, you can get contaminants in the cabinet, things will prematurely fail. It may seem rudimentary but there are a lot of different options to consider. I want to tell you about the 6 that I think are the most important.
1. The environment is critical in picking the right cabinet. If this is going to go anywhere where water or dust or any type of contaminants are present in the atmosphere then you want to make sure your cabinet has some sort of seal on it so that you can remember to keep the water and the dust out, that’s the main thing. You want to make sure there isn’t going to be too much heat in the cabinet. You want to make sure that the components have room to breathe. So again all kinds of enclosures exist, each application is unique, the enclosure should be unique as well. The smallest enclosure is not always the best enclosure. You may want the smallest enclosure because space = cost. The bigger the enclosure the more it’s going to cost because the more metal there is. Just think about the long term maintainability of all the equipment that you are going to put inside of it. It is not easy to change an enclosure once you decided and installed all the components so make sure you take the time to get it right. Consider all the options; way all the pros and cons and make an educated decision. So again the first thing is going to be the environment that dictates the type of enclosure. That’s going to be the NEMA or the IP which means Ingress Protection rating that’s going to keep all the contaminants out of the cabinet.
2. The internal components that are going to go inside. Most of the time it’s going to be electronics inside and those electronics produce heat. All these electronics have an associated watt loss, heat loss that’s associated with them. That’s usually part of the specification for each of these components. Add all that up and make sure your cabinet can dissipate that much heat. There are calculations you could use to determine that.
3. The need to access all the different sides of the components. For instance, if you need to get your hand up underneath here to grab a hold of this wire and it’s too close to the wire duct you can’t get your hand in there. Same thing if I need to be able to grab the in stop on the side of the piece to pull it off of the din rail. If I can’t get my hand in here it’s going to make it a lot more painful for me to do that if I’m a maintenance person. Remember you want to make enough space in here for things to be able to breathe and for you to be able to access these things with your hands.
4. Surrounding obstacles outside of the cabinet.Anything that is going to be on either side or the front or back is going to determine how big your door needs to be. If you have any cables that have to come out with a minimum bend radius or anything like that. That’s going to affect how far away you need to place things from the cabinet. If there is going to be any corrosives in the environment, if it’s a wash down say for a food and beverage application the type of enclosure you’re going to want to make sure it’s stainless or something that can’t corrode with cost of chemical wash down.
5. Think about any arc flash mitigation that you have to deal with. Certain customers of ours require the internal disconnect be located on the outside of the panel completely, so when power is removed there is no internal components that will have live power to them. Think of your maintenance personnel when you pick these component because it can really mean the difference between being able to work on these efficiently and effectively to reduce downtime. Make sure you can prolong the life of the equipment inside, which has to do with heat loss and contaminants.