Three phase elevator, single phase power

hmspe

Senior Member
I'm working on a relatively small commercial building that was designed at 208/3. A Thyssenkrupp 25HP elevator (Endura 21 A with integral solid state starting) has already been installed. The elevator documentation specifies 208/3 but does not have a voltage tolerance stated.

2+ years into construction the building does not have utility power connected, and the utility's rules have changed and they now cannot serve the building with 3 phase because of right-of-way issues. All that is available is 120/240/1 at 800 amps max. I expect that this will be on a transformer shared with other shops. Changing to a single phase elevator is not an option.

I'm looking for suggestions on the best type/make/model of phase converter for this application. I'd like to use a static converter, but I can't find any literature on using a static converter to supply a device with a solid state starter. If the converter needs to be rotary are there any things to look out for?

Thanks.
 

hmspe

Senior Member
Thanks for the replies. PhasePerfect was the manufacturer I was leaning toward. This is my second phase converter project in 35 years as a PE. I'm a bit out of my element.

The general contractor has been the one who has contacted the elevator manufacturer. He reported "They cannot sign off on this phase converter [PhasePerfect] but did provide some constructive comments to help. The largest point is that it needs to meet their power requirements with a maximum 10% +/- differential. They reiterated that they have seen Ronk phase converters used numerous times and feel that searching that supplier might allow us to find what is needed."

They did not say which of Ronk's product lines they've seen. The +/-10% they mentioned is also not in the manufacturer's shop drawings for this project.

I suggested having Thyssenkrupp change to a controller with a single phase input. I was told that is not an option.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
It would be cheaper and more reliable to just change the motor to 240V single phase...

Soft starters, ESPECIALLY the ones used for elevators made by Siemens, do NOT like to have "manufactured" 3 phase power of any sort because the timing between phases is incorrect, which messes with the firing timing of the SCRs.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Contact the elevator manufacturer. Converting it to single-phase power might be as simple as swapping out the VFD.
Anything used in a passenger elevator must be specifically UL listed for that use, so you can't just use any VFD on them. UL listing for elevators is a quantum leap more difficult to get than a regular UL listing, even for things like contactors. A few of the elevator mfrs have done it with specific VFDs, but most VFD mfrs want nothing to do with it because of the liability issues.
 

Besoeker3

Senior Member
Location
UK
I'm working on a relatively small commercial building that was designed at 208/3. A Thyssenkrupp 25HP elevator (Endura 21 A with integral solid state starting) has already been installed. The elevator documentation specifies 208/3 but does not have a voltage tolerance stated.

2+ years into construction the building does not have utility power connected, and the utility's rules have changed and they now cannot serve the building with 3 phase because of right-of-way issues. All that is available is 120/240/1 at 800 amps max. I expect that this will be on a transformer shared with other shops. Changing to a single phase elevator is not an option.

I'm looking for suggestions on the best type/make/model of phase converter for this application. I'd like to use a static converter, but I can't find any literature on using a static converter to supply a device with a solid state starter. If the converter needs to be rotary are there any things to look out for?

Thanks.
Static one phase to three phase with a three phase solid state starter on the output?
 
Anything used in a passenger elevator must be specifically UL listed for that use, so you can't just use any VFD ...
I know that. I presumed that the elevator OEM makes the same elevator in both 1-phase and 3-phase configurations, and that they could swap out their listed 3-phase components and swap in their listed 1-phase components.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
The GC.

The general contractor has been the one who has contacted the elevator manufacturer... I suggested having Thyssenkrupp change to a controller with a single phase input. I was told that is not an option.
2+ years into construction the building does not have utility power connected, and the utility's rules have changed and they now cannot serve the building with 3 phase because of right-of-way issues.
You say that this is a relatively small commercial building. Was 2+ years originally scheduled for this project or were there circumstances that caused delays? Why wasn't utility power brought in sooner?

Sounds like there is a lot more to this story and now somebody doesn't want to pay up, not that it can't be done.

-Hal
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
The GC.

Sounds like there is a lot more to this story and now somebody doesn't want to pay up, not that it can't be done.

-Hal
I agree with this.
With todays technology, the only reason this can’t be done is money issues.
 

hmspe

Senior Member
I really don't know much about the construction history of this project. I did the design for the original building as a restaurant. A year later I redid the design for a different architect as a medical/spa building. I did not have a construction administration contract either time. In this area the electrical contractor or the owner sets up the account and does coordination with the utility. This is in a large existing shopping center on a major street in a large city with other buildings which are three phase so there was no reason to assume that three phase was not available.

Now the building is going to be shell only. The current general contractor signed off on the elevator. I never saw a submittal and to the best of my knowledge neither did the architect. As far as I can tell the utility was never contacted until after the elevator was signed off.

The GC told me that Thyssenkrupp told him that it would cost as much as a new elevator for them to convert this to single phase. I don't know how that compares to a Ronk phase converter plus a 240/3 to 208/3 transformer. Thyssenkrupp said they had seen Ronk used many times but would not recommend a specific model.
 

brantmacga

Senior Member
Location
Georgia
Occupation
Electrical contractor
Call Ronk and let them recommend the model.
I would definitely call Ronk first and tell them exactly what you are doing.

I bought one for some motors at our farm last year and ended up having to build a panel with time delay relays to start them in a particular sequence or it overloads and trips the breaker. I bought what Ronk recommended but didn’t tell them the application; they told me afterwards had they known what I was doing (grain unloading augers), they would’ve told me to replace my motors with single phase. They said it is not designed for starting motors under load. And the rotary converter has to run for at least 10 seconds before starting a 3-phase motor.



Sent from my iPhone using Tapatalk
 

hmspe

Senior Member
I contacted Ronk and gave them the make, model, and load information. I specified what they recommended.
 
Top