Required Power for Tower Crane

Will all the motors be running at full load simultaneously?

You should post this question in the Electrical Engineering Section . . . most of those electrical types think us mechanics are a bunch of wingnuts, so they open the main isolation and try to avoid us, lol

Nuke, us electrical types do not think you mechs are wingnuts, if you guys didn't break things we'd be out of a job, LOL

Happy New Year

Thanks Brich . . . I was joking . . . but I do also understand our primary need in the scheme of things . . . my dad was an electrical type . . . wow did he get torqued when I would tear apart the dishwasher or refrigerator to see how they worked!!! But he always put them back together with lots of black electrical tape, lol

You are welcome 629.

Now my dad my was the mech type and I used to take EVERYTHING that had screws or had a removable case apart and my Dad would spend hours putting it back together, as new.

Wound up would not begin to describe how he was after several hours of repairing what I'd dismantled

He knew his day would be spoilt by my famous words.. "How does this work Dad?", cos I couldn't put it back together again.

He prevailed where all the "Kings Horses and all the Kings Men" failed

In some jurisdictions, you may have to do as lynlynch describes: add up all the kw's even if some may be idle. In others, you may be able to specify the maximum set of concurrently running motors, and size for that. Plus you have to add some multiple of the largest motor amps for calculating feeder conductor, circuit breaker, and/or fuse size. These factors may vary by local codes. (I've designed/built UL-508 panels in the past, but right now I forget the NEC factors.)

many thanks

Yes, add ALL the KW together. Is there a BIG chance that ALL the motions will operate at once?

Yes there is if the crane operator is good. Having worked in a Steel Works maintaining the cranes, I would notice the operators using all motions at once, and in some cases with a crane with two hoists, both hoists and both travels would operate at once.

You must also take into consideration the auxillary power, lighting, A/C or heating.

However what does the manufacturer tell you?

Agree with lynlynch, Tornado + Birch. You have to allow for all motors running simultaneously at max load.

A good crane operator will almost always use all available motions if circumstances allow. This is particularly true of RMGs and EOTs. Tower cranes not so much because of operating conditions + the rotate motion is limited by the physical design of the crane; i.e., you don't want to turn it into a carnival ride.

many thanks

Add all the motors that can operate at the same time and then add 25% of the largest. This will be the electrical feeder size. Example: (1) 40hp, (1) 20hp & (2) 10hp, 40hp = 52 amps @ 480v, 20hp = 34amps, 10hp = 14amps 52amps + 34amps + 2 x 14 amps + .25 x 52 amps = 127amps @ 480 volts 3 phase