Escalators

[maunsell]

Good afternoon chaps
i have been asked to look into the 2 different methods of drive control for escalators, that being tradiontal methods and a VVSD( voltage Variable Speed Drive) which i believe consists of a frequency regulator. I have been tasked with assessing whether or not it justiifes the expenditure.

does this forecasting depend upon the speed the escalator is set up upon. As you can probably gather i have had no dealings with escalators todate and therefore would appreciate any assisting.

Manufactuers are telling me that upto 60% savings can be made, others tell me if you use the tradiontal method on star only 8 % savings can be made. However for VSSD control only adds 10% to the capital costs.

if any one can help , iwould be eternaly grateful, Honest

Regards
Maunsell

 

[dydt]

hi..
how often do you have to change the speed of an escalator anyway?

manufacturer said 60% savings on what?..consumption or cost of the modification..

i do know that a VFD is reliable but you have to convert your motor to an inverter duty...DC on the other hand has the nuisance of cheking the brushes and powderized carbon build-up around the commutator area...on its AC motor counterpart you don't have this problem..

dydt

 

[maunsell]

Quick response, very impressive
unsure of the change of speed ,although i understand that it can be done according to the load profile according to the type of building?

The 60% savings are related to the running costs over a year.~With would therefore justisfy the 10% uplift on the capital costs?

This installation is a new one of which no installation works has beeb undertaken at present and therefore the client has raised the question of payback

 

[dpc]

I would be very skeptical of any claims of 60% energy savings.

The adjustable speed drive adds complexity as well as cost, so you need to consider implications of downtime related to drive failure, maintenance, spare parts, etc. If you go with the drive, you may want to consider specifying it with a bypass contactor so the motor can be run at full speed when the drive is down.

When looking at energy savings, keep in mind that the motor will be less efficient operating from the drive than from a sine wave and that the drive has losses that must be considered.

Running the escalator slower does reduce energy consumption, but how much does the escalator contribute to the overall energy usage in the building? Probably miniscule.