HOIST CLINIC WITH ACE INSPECTION MANAGER JERAMY NICHOLS
Splicing is the process of combining two different pieces of wire together to form one continuous wire that will carry an electrical current. Splicing, in practice, allows you to avoid installing new wires by connecting used, damaged ones—a quick and dirty alternative to investing in new wire.
According to the National Electric Code NEC/NFPA 70-610.21(g), as well as other regulatory agencies and original equipment manufacturers, it is not advisable to splice the wire that feeds power to your crane’s hoist. Since the hoist trolley moves back and forth on a crane’s I-beam, it requires any attached wiring to be flexible enough to accommodate the range of motion. If spliced, the hoist wire loses the strain relief normally provided by its insulated outer coating and it could break if stress is put on it.
Examples of compromising spliced hoist wires.
Imagine if you had an extension cord and you cut it and spliced the wire within it together then pulled on either end. That extension cord would pull apart. The spliced wiring is not going to be strong enough to hold together. In the same way, you’ll want to make sure that any festoon wiring you use for your crane’s hoist has the proper flexibility needed.
Splicing with wire nuts, or what they call “butt splices”, where wire connectors are slipped onto the ends of wire and twisted together, are not recommended at all. A connection like this would not hold the needed tensile strength. Also, if the connecting wires become overloaded or loose, they can overheat and cause sparks. If you are not cautious and allow these wires to stay in the open, then those sparks could cause a fire. This would create a grave danger in highly combustible working environments. Wire connections using wire nuts need to be terminated in a fire-resistant box. They are not appropriate for hoist wiring.
There are other drawbacks to wire splicing as well. The more splices you have made in your wiring, the more your voltage and amps will drop because you won't have a smooth, continuous current running through it. Also, there are dangers associated with wire splicing. Beware that if any spliced wiring were to come apart, it could create a potential shock hazard for the crane operator!
Even without splicing, power and control cable can become brittle and lose connectivity due to internal breakage caused by aging or environmental fatigue. Internal breakage can result in intermittent control issues affecting crane motions or power issues causing single phasing to motors and premature failure. If you’re splicing due to deterioration in your wire, you’re likely to be chasing ghost issues going forward. If you’re replacing components, especially if they have repetitive issues, you’ll need to look downline to make sure you’re addressing the root cause of the issue.
For best results, we recommend replacing your hoist power wire when it breaks and avoid the temptation for a quick, cheap and easy fix like wire splicing. It will cost you more in the end in terms of safety and performance and will most likely create the inconvenience of re-breaking down the line, anyways. If you have any questions about wire splicing or related crane or hoist issues, feel free to reach out to me at (904) 430-3598 or firstname.lastname@example.org.
Author Jeramy Nichols
Jeramy has been in management for 27 years from auto part sales, heavy equipment repair, military helicopter production, and compressor production. He attended Troy University for Business Management and Auburn University for Lean Manufacturing/Six sigma. Since 2012, Jeramy has served Ace in various rolls in service with working in the field, inspection review, repair quoting, InspectALL admin, and inspection training. Jeramy is also part of ASME B30.16 and B30.17 subcommittees, and CMAA Safety/Service and Spec #76 committees.
Jeramy lives in Troy, Alabama, with his wife, 3 daughters and 1 son, 1 grandson and 2 more grandchildren on the way, 2 dogs, 5 chickens, and a goat. He enjoys spending time with his family and friends, working on the farm and being outdoors.
Jeramy believes TEAMWORK consists of 3 aspects: Cooperation, Communication, and Support!