Transportation of Protection Panels with Relays Mounted

[DiscoP]

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.

 

[dpc]

It's done all the time. I would specify an air-ride trailer and **enclosed**.

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.

 

[jraef]

What dpc stated is exactly what we do. Installed, but air ride, dedicated trailer direct to the jobsite. We discovered (the hard way) that if you don't say dedicated trailer to the jobsite, the local drayage service that gets used can sometimes do more damage in the last 10 miles than it suffered in the previous 2000. I had one get to a jobsite and since nobody remembered to call for a fork lift, he literally pushed the gear off the back of his tailgate face down in the mud and drove off angry. Sure the insurance covered the replacement, but the time lost is never covered.

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[waross]

This is probably an issue that no longer exists. On a large project in the late 80's there was an excessive failure rate of the computer interface cards in the motor control centers.
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.

 

[rcw retired EE]

We always have the relays shipped in the switchgear or panels with no special shipping requirements. Some suppliers put packing material in front of a glass cover relay, most don't. I only recall a few broken covers and no relay problems in many years of both domestic and over seas shipping. It saves a lot of time on site.

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.

 

[dede61]

We work in the same way, the panels are exposed to FAT with the customer, then transported the the building site where the final commisioning takes place + SAT. It has alway been the case as far as I can remember.

regards,

Danny

 

[buzzp]

The only ones I would worry about would be the electromechanicals.

 

[patrick7]

I am in agreement with you that haveing the panels wired and relays mounted does save a lot of time in the field.

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.

 

[sdugre]

This is what can happen when panels aren't crated for shipping correctly:

http://www.hged.com/MVC-008F.JPG

http://www.hged.com/DSC-00943.JPG

http://www.hged.com/MVC-002F.JPG

Good thing it was FOB.