Bricktown mixing water& electricity

[dennishoddy]

Seems like an odd voltage. 3-phase perhaps?

Might explain the absence of a ground.

480 three phase includes a safety ground.

 

[dennishoddy]

An Overview Of 277 Volt Electrical Systems
Industrial and commercial power is delivered in 120/208-Volt and 277/480-Volt systems. Heating and ventilation systems are run at 480 volts while industrial scale lighting runs at 277 Volts. A 277/480-Volt system powers the industrial and commercial equipment at 480 volts while the 277 volt wiring powers the lights.

Electrical discharge lighting is designed to run on 277-volt wiring. A three-phase, four-wire distribution system running at 277 volts is used for high voltage lighting like LED arrays and fluorescent lights. Electricians can run 277 volts off 480-Volt AC circuits.

A 277/480V, three-phase system can provide single phase or three-phase power at 277 volts or 480 volts. Electrical distribution systems with 277-Volt wiring use step down transformers to provide either 240-Volt or 120-volt power as required. Residential AC circuits use power at 120 amps and 277 volts. Wiring of a 277/480-Volt system can supply both industrial and residential users. Using 277-Volt wiring permits more lights to be powered by a single branch circuit. This reduces the amount of high voltage wiring that must be installed to connect banks of LED or fluorescent lights, or appliances.

Well, I posted before seeing you had already done the research. I worked with 480V systems and much higher for my entire working career.

 

[MacFromOK]

480 three phase includes a safety ground.

Unless the original/ancient wiring only has 3 wires...?

Just curious, I really don't know that much about 3-phase.

 

[dennishoddy]

Unless the original/ancient wiring only has 3 wires...?

Just curious, I really don't know that much about 3-phase.

You can have three wires off the transformer depending on the style of the transformer, but an earth ground is used in that case.

 

[MacFromOK]

You can have three wires off the transformer depending on the style of the transformer, but an earth ground is used in that case.

Well... apparently not in this case. :/

 

[dennishoddy]

Well... apparently not in this case. :/

Fault of the installer possible, but the NEC does allow for grounding through the conduit connection or grounded through the appliance with a strap. There are TV reports that many of the bollards in question were loose in their moorings, so if they used the connection for a ground, it's entirely possible the scenario that happened did so because of that.

 

[MacFromOK]

Good point.

 

[okierider]

Would a ground have made any difference? Bollard went into the water along with the fellow who died. Reads like the bollard or mount snapped or the screws sheared off.

 

[SoonerP226]

Seems like an odd voltage. 3-phase perhaps?

Might explain the absence of a ground.

277 is common in non-residential lighting. All of our fluorescent lights at work were 277V.

 

[SoonerP226]

Well, I posted before seeing you had already done the research. I worked with 480V systems and much higher for my entire working career.

I talked to a commercial HVAC tech who did lots of work on our system at work. He said he didn't worry about 480 or under, as you had to touch it for it to hurt you. A lot of the stuff he worked on would reach out and grab you...