Old Transfer switch - needs delay?

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sfav8r

Senior Member
I have been asked to help a client with a problem that started with the installation of a new elevator. After the installation of the new elevator, the emergency transfer fails. When this was first discovered, they were told by the elevator company that their generator was too old to handle the new elevator equipment and that a new generator would have to be installed. I believe the assumption at that time was that it was a phasing problem and the old generator/regulator could not respond fast enough. Now, one of the people involved says that the problem is the transfer switch and that the switch should be changed or a delay should be installed in the ATS.

This is an area I have very little experience in. However, I have worked with the client for a long time and they trust me to help them get to the bottom of this since different people are telling them different things. I am setting up a meeting with the elevator company and the generator company to do some fact finding and would appreciate any input from anyone with experience doing this.

The plan at this point is to determine the following:

1) What EXACTLY is the failure? Does the generator shut down or does the transfer work correctly but the elevator shuts down?

2) What does the elevator company mean specifically when they say a delay is needed?

3)What are the requirements of the elevator in terms of phase accuracy/power qulity? - What are the capabilities of the generator?

One thing that is puzzling me is that to be compliant with the local codes, they currently have a mobile genset connected. If the transfer switch is the problem, what good is the mobile genset? It would be using the same ATS.

What question would you want answered? I just need to help them determine what the real problem is and then find someone with a strong background in this area to complete the work. I would be happy to pay a consulting fee to someone sharp in this area. If that's you, feel free to PM me. Also, if someone knows someone in the SF Bay Area that knows this stuff in their sleep, it may be an opportunity to do the repair/installation.

Thanks
 
Did the old elevator have a MG set and the new one a VFD? Does the generator have a mechanical or electronic governor? I'm wondering if harmonics from a VFD would be upsetting the generator controls. 'course, that's just a stab in the dark.
 

ATSman

ATSman
Location
San Francisco
Occupation
Self Employed
Elevator Pre-Signal

Elevator Pre-Signal

I have been asked to help a client with a problem that started with the installation of a new elevator. After the installation of the new elevator, the emergency transfer fails. When this was first discovered, they were told by the elevator company that their generator was too old to handle the new elevator equipment and that a new generator would have to be installed. I believe the assumption at that time was that it was a phasing problem and the old generator/regulator could not respond fast enough. Now, one of the people involved says that the problem is the transfer switch and that the switch should be changed or a delay should be installed in the ATS.

This is an area I have very little experience in. However, I have worked with the client for a long time and they trust me to help them get to the bottom of this since different people are telling them different things. I am setting up a meeting with the elevator company and the generator company to do some fact finding and would appreciate any input from anyone with experience doing this.

The plan at this point is to determine the following:

1) What EXACTLY is the failure? Does the generator shut down or does the transfer work correctly but the elevator shuts down?

2) What does the elevator company mean specifically when they say a delay is needed?

3)What are the requirements of the elevator in terms of phase accuracy/power qulity? - What are the capabilities of the generator?

One thing that is puzzling me is that to be compliant with the local codes, they currently have a mobile genset connected. If the transfer switch is the problem, what good is the mobile genset? It would be using the same ATS.

What question would you want answered? I just need to help them determine what the real problem is and then find someone with a strong background in this area to complete the work. I would be happy to pay a consulting fee to someone sharp in this area. If that's you, feel free to PM me. Also, if someone knows someone in the SF Bay Area that knows this stuff in their sleep, it may be an opportunity to do the repair/installation.

Thanks
SF
I think I can help you wirh this as I have several proposals in place right now to add the elevator pre-signal modification to ATSs in downtown SF. I have been working on ATSs in the SF Bay Area for 37 yrs. The old elevator controllers did not care if the ATS transferred when the cars were moving. When elevator controls are upgraded from relay logic to solid state controls the cars cannot be in motion when the ATS transfers between hot power sources (hot bus-hot bus.) The SS logic cannot handle it and it can cause damage to the controller (blown caps and PC boards.) To deal with this, a pre-signal (pre-transfer) is sent to the elev controller prior to transfer to send the cars to the nearest floor and open the doors. The system resets after the ATS transfers and the cars go on there merry way. I not sure if I remember how to IM to talk with you further and do not know the rules about leaving emails or phone #'s.
Hopefully you will read this.

Tony
 

sfav8r

Senior Member
SF
I think I can help you wirh this as I have several proposals in place right now to add the elevator pre-signal modification to ATSs in downtown SF. I have been working on ATSs in the SF Bay Area for 37 yrs. The old elevator controllers did not care if the ATS transferred when the cars were moving. When elevator controls are upgraded from relay logic to solid state controls the cars cannot be in motion when the ATS transfers between hot power sources (hot bus-hot bus.) The SS logic cannot handle it and it can cause damage to the controller (blown caps and PC boards.) To deal with this, a pre-signal (pre-transfer) is sent to the elev controller prior to transfer to send the cars to the nearest floor and open the doors. The system resets after the ATS transfers and the cars go on there merry way. I not sure if I remember how to IM to talk with you further and do not know the rules about leaving emails or phone #'s.
Hopefully you will read this.

Tony
Thanks Tony, I got your PM. I'll give you a call today.
 
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