Transportation of Protection Panels with Relays Mounted
Transportation of Protection Panels with Relays Mounted
(OP)
There is a bit of debate within our organisation about transportation of protection panels with the relays installed.
Some people want to wire and test protection panels in the workshop, then transport the panels to the site with the relays in place. They relays are mainly modern numerical devices with some electromechanical tripping relays.
I can understand their reasons for wanting to do it, however they are asking for the group I am in to approve this process to cover themselves.
Our initial thoughts are to say no, but cannot think of any good reasons - other than there is more protection for the relay when it is back in its carton, but I wonder whether this is a little pedantic.
Does anyone have any good or bad history of transporting relays on panels.
Some people want to wire and test protection panels in the workshop, then transport the panels to the site with the relays in place. They relays are mainly modern numerical devices with some electromechanical tripping relays.
I can understand their reasons for wanting to do it, however they are asking for the group I am in to approve this process to cover themselves.
Our initial thoughts are to say no, but cannot think of any good reasons - other than there is more protection for the relay when it is back in its carton, but I wonder whether this is a little pedantic.
Does anyone have any good or bad history of transporting relays on panels.






RE: Transportation of Protection Panels with Relays Mounted
You should specify that it be shipped in a dedicated tractor/trailer straight from the shop to your site. And buy it FOB jobsite. If you're really worried, you could specify impact recorders...
The advantages of having the relays installed, wired and tested at the panel shop far outweigh the shipping risks, at least in my opinion.
Metal-clad switchgear is routinely shipped with all relaying mounted on the front doors of the cubicles.
RE: Transportation of Protection Panels with Relays Mounted
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: Transportation of Protection Panels with Relays Mounted
The theory was developed that the damage was being caused by the electricians welding the MCC sections to angles cast in the concrete floor for that purpose. Welding was banned. It didn't make any difference to the failure rate. The MCC sections were wrapped in plastic sheets. When they were to be installed they were typically lifted off the warehouse truck with a crane using insulated slings. While the MCC was suspended in the air, the electricians would pull the plastic wrapping off. I really suspected that electrostatic discharge was the cause of the failures.
But I guess these days electronic devices are well protected against ESD.
RE: Transportation of Protection Panels with Relays Mounted
I did loose components when the plastic wrap was left on the MCC as it sat in a holding area at the jobsite. Sunshine melted control knobs, nameplates and indicating light lenses.
RE: Transportation of Protection Panels with Relays Mounted
regards,
Danny
RE: Transportation of Protection Panels with Relays Mounted
RE: Transportation of Protection Panels with Relays Mounted
However, even if the relays are delivered to your base facility. Taken out of the box tested, installed and wired into panels, tested in the panel then shipped to the site and installed; I am of the opinion that these panels once installed in the substation have not been proven.
I dont have any problem with prewired panel arriving at the job site. However before placing them in service I always require that the relay system be proven. (which is tested at the final location, and settings verified. We also prove the system by injecting current at the breaker and test the entire wiring system.
I would be inclined to approve the prefabricated panels with the stipulation that the system be proven once installed.
Record keeping is also a big issue. Since they want your department to approve this sounds like finger pointing, trying to blame shift if something were to fail. So I would insist that the system be proven in the field and highly accuracte records be maintained.
RE: Transportation of Protection Panels with Relays Mounted
www.hged.com/MVC-008F.JPG
www.hged.com/DSC-00943.JPG
www.hged.com/MVC-002F.JPG
Good thing it was FOB.