Generator for elevator

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olc

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(Getting info from the generator manufacturer and esp. the elevator manufacturer is not an easy process.)

We are sizing a generator for standby for an elevator only.
The elevator is a Schindler machineroomless traction.
The building voltage is 208V but I think Schindler uses a transformer and 480V drive. (trying to verify)
So I am concerned about the inrush starting current.
Have you seen this application?
 
Caterpillar and Cummins have web based programs that can assist with sizing a generator. They aren't gospel but are a good starting point. They tend to oversize (surprise, surprise)

Google:
SpecSizer Caterpillar
PowerSuite Cummins

I'm not sure, but Generac or Kohler may have sizing programs if you want a more commercial grade (cheaper) generator

Is the elevator existing?
Is there a manual available?

Try and find the electrical specifications. It would help if you had the running load, starting amps, and drive type (ATL or VFD).

If there is a transformer between the elevator and the power supply, you want the nameplate for that as well.
 
The last 3-4 projects I’ve bid recently with traction elevators specified battery backup w/ inverter for the elevator. That would be provided by the elevator installer, so I don’t know the cost, but it’s likely far less expensive than setting up a generator for just an elevator.

As for using generac like someone mentioned, only a couple specific lines are NFPA 110 compliant as being compatible with an annunciator.


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I'm using the Generac program.
New elevator. In contact with them but can't get a straight answer.
This project needs the standby generator.
I'm sending another very specific question today.
 
Kholer does have a program too. Its called Power Solution Center. Each one has their own quirks.

I haven ever used Generac program. Be very careful when using it. Garbage in = garbage out.

As ron mentioned, inrush is not as much of an issue with drives, however, what is an issue and has generator installations to not be sufficient are the harmonics that the drive produces and the generator not being sized large enough for them. In addition, elevators have moment of acting as an overhauling load. Long story short, the way the load acts makes the DC bus voltage on the drive increase. There are two ways to deal with this. 1. Either use a Dynamic braking resistor and bleed that energy out as heat to get the bus voltage in check, OR 2. Send that energy back into the electrical grid. This is great energy savings for when you are on utility, however, if you are on a gen the alternator may not be able to absorb that so that generator needs to be upsized to take that or have a DBR put into the system whenever on generator power.
 
The issue is a transformer - the literature said something like 10X amps for 1 sec.
Just thinking aloud- bear with me - if the building loses power, the generator will start, the transformer will energize long before the elevator runs and puts a load on it?

The other issue that just came up - Schindler elevators have a SCCR of 5KA and the SCCA is >5KA. (not an issue if there is a transformer)
 
olc said:
We are sizing a generator for standby for an elevator only.
The elevator is a Schindler machineroomless traction.
The building voltage is 208V but I think Schindler uses a transformer and 480V drive. (trying to verify)
So I am concerned about the inrush starting current.
Click to expand...

olc said:
The issue is a transformer - the literature said something like 10X amps for 1 sec.
Just thinking aloud- bear with me - if the building loses power, the generator will start, the transformer will energize long before the elevator runs and puts a load on it?
Click to expand...
Could you use a 480V generator to avoid having the generator drive a transformer and supply its inrush current?


olc said:
The other issue that just came up - Schindler elevators have a SCCR of 5KA and the SCCA is >5KA. (not an issue if there is a transformer)
Click to expand...
By the way, the 208V to 460V 32kVA autotransformer for an elevator in the post at the link below has an impedance of only 0.85%, and so it will not provide much of a reduction in the SCCA. An isolation transformer might be more suitable in your application.

https://forums.mikeholt.com/threads/elevator-boost-transformer.2569261/post-2772116
 
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