Have a customer with 2 US Elevator cars, both hydraulic looking to do a mod to tank controller and wiring/some electrical. they have handicap tenants in the building so we are looking to mod the slave car first to leave the master car in service for handicap accessibility, working on the master once the first mod is completed and running. Their current company says it cant be done, im almost certain there is a way, even with cars this old (80s). Trying to get by the site to look but wanted to see if anyone had any experience with taking one out of service for a mod while leaving the other in normal operation.

Thanks for any help.

Tom