Did you know that most hoists manufactured today have only one brake? In the event of a motor coupling, brake failure or power loss most hoists made today will drop the load at the maximum rated speed of the hoist. That’s pretty frightening! But, hoist users can cost-effectively increase the safety of their operation by specifying hoists with a backup braking system that protects against those risks.
Modern designed European style hoists have for the most part replaced the heavy ANSI style hoists in years past. These newer hoists like compact cars are lighter and much less expensive. When applied properly their expected life is 5 to 10 years. One of the safety features missing from as a standard European style hoist is a secondary mechanical load brake. The mechanical load brake in the ANSI style hoist was located within the gearbox of the hoist and would stop the load in the event of a motor coupling, motor brake or shaft failure. The mechanical load brake was comprised of a ratchet and pawl mechanism that was expensive and generated heat in the gearbox.
Most European style hoist manufacturers place the hoisting brake at the back of the hoist motor which happens to be the most vulnerable spot. You are only one motor coupling failure away from a dropped load which is exactly why loads should never be left suspended and never ever suspended over workers or valuable equipment.
Street Crane, one of CRANE 1’s featured hoist suppliers has a much safer standard hoist braking system and offers two economical additions to improve safety and reduce the chance of dropped loads.
The standard Street series of hoists are comprised of three frame sizes ZX6, ZX8, and ZX10. All three of those designs have the hoisting motor on one side of the gearbox and the hoisting brake on the other side of the brake. A motor shaft or coupling failure will have no impact on the ability of the brake to stop the load on operator command. Street also offers a secondary brake that can be mounted on the back of the hoisting motor. This would add protection in case the gearbox mounted brake fails for some reason. This double brake design is a huge safety improvement above other European designed hoists.
On more inexpensive feature is the use of an over speed sensor within the gearbox. Should the sensor determine that some failure has caused the hoist to over speed; the primary and secondary hoist brake will be instantaneously engaged, stopping the load in milliseconds. This over speed device can be fitted to both the single and two brake design. The cost of adding both options is well under 20% in addition to the hoist price and add huge peace of mind to the safety of the operation and equipment.
Should you have any questions on these safety features or how to make your existing equipment safer, give CRANE 1 a call and our local experts can assist you.