Buying the right electric chain hoist can be confusing, but with these simple tips it will help lead you in the right direction. With a little work it can be an easy task and you will have the right hoist for your application.
1. Capacity of the hoist. Hoists are designed for a 5 to 1 safety factor mechanically so you do not have to put in your own safety factor. That being said it is prudent to not buy a hoist that will be picking up the maximum load throughout the day. An example is a 10 ton hoist operated at a mean effective load of 5 tons will have a bearing life 8 times that of the hoist run at its rated capacity.
2. Running time of motors. How will you run your hoist? Most hoist motors are rated as 30 minute rated which means 30 minutes on and 30 minutes off. You cannot run your hoist for 4 hours of the shift and rest the hoist for 4 hours. You need to have an even time of running and resting not to exceed 30 minutes (or whatever your hoist motor is rated).
If you have a high duty cycle you may want to consider an air hoist or electric hoist with 60 minute or continuous duty motors.
3. Special conditions. Is the hoist going to be in a combustible environment, hot metal (molten), wet, humid, corrosive or high ambient temperature? Then special enclosures, braking systems, fans, limit switches or motors may be required.
It is recommended you work with an experienced sales engineer to make sure the proper hoist accessories are provided. They are too numerous to list for each potential application. That being said an air hoist can be provided in many applications that require spark resistance.
4. What will the hoist be suspended from? A hoist can be provided with several suspensions. They include top hook (which can work with a stationary beam clamp or push trolley), plain push trolley, hand geared trolley or motorized trolley. For light capacity and light duty hand push can be desirable. If you need precision but do not need to move the hoist very far then a hand geared trolley is an excellent choice. If you have to move the trolley very far, very often, or if the capacities dictate then a motorized trolley is preferable.
It is hard to give a capacity break down because for some applications a 5 ton push trolley is fine but would not work for other applications. An experienced hoist sales person can guide you in the right direction.
5. How much lift do I need? Chain hoists can be used for longer lifts but it is important to consider the number of chain drops (Reeving). You can end up with a very large chain container and heavy hoist if there is too much chain. Electric wire rope hoists are typically used for long lifts. Three ton and above with lifts exceeding 35′ is a generic cut off point to go from chain hoist to electric wire rope hoist.
Remember you can deduct the headroom of your hoist from the lift required but do not forget to account for any pits you may be going into to make you lift.
6. Control on hoist and trolley. Depending on your application a simple single speed control may work for the job but if your product is expensive, requires delicate placement or fragile you can look at two speed or even variable frequency control on the hoist and trolley.
7. Special considerations. There are other items that need to be discussed. Most hoists come with an upper and lower limit switch which will limit your upper and lower travel. Many do not come with an overload (over capacity) limit as standard and this is worth discussing with your sales professional. It can prevent damaging your supporting structure and the product you are lifting, especially if the product is held in place by some type of fixture.
There are numerous types of limits which can include over travel, and control circuit which need to be discussed in detail with your sales person.
As with any piece of engineered equipment there are many options available and may need to be looked at in person by a qualified person. These guidelines will prepare you to ask the right questions.
Source by Matt Timme
