Electrical Tip Of The Day

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RustyRatRod

I was born on a Monday. Not last Monday.
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@67Dart273 This is for you Del. lol

KINK.jpg
 
Lord.

AND NOW, an annoying story from the old days

When I first got into HVAC, we got a call on a rooftop unit in downtown Spokane, "old OLD building." We had to remove the blower. But there is a PROBLEM

Many? most? rooftop units have a dedicated entry for the AC power, usually down low on the cabinet. For whatever reason --this one was installed long before codes got stiff or enforced-- the installer had come up through the roof with conduit, run it neatly right into the unit, BUT WAIT!!! there is no DISCONNECT!!

So they had mounted a nice big 3 pole (this was 3 phase) disconnect right on top of the cabinet RIGHT on top of the blower compartment, then run the three incoming hot wires from the entrance, up through the blower compartment to the disconnect, through the disconnect, and then run the three power feeds to the unit back down through the blower compartment--to tie in to the power entrance below it.

So when you remove the blower access panel you have SIX conductors running vertically from top to bottom RIGHT IN FRONT OF THE BLOWER. (sort of like a jail cell LOLOL)

So you pull the disconnect, you STILL have three wires that are HOT

Well, we go down below, we looked and looked, and asked anyone we found, and COUND NOT find whatever breaker/ fuse fed that circuit

Finally, we pulled the six "cold wires out of the way, then CAREFULLY, standing on a wood box, with plywood leaned up against the unit for insulation, ---one at a time, removed the "hot" wires and taped them off, then pulled them out of the way.........

Replaced the motor, serviced the unit, and put all the wires back.

At the time I even briefly came up with the bright idea, "let's throw a wrench across the switch, turn it on, and see what breaker trips"

IT TURNED OUT A FEW YEARS LATER that building suffered a little fire. And that AC circuit was a completely illegal "tap" in a wire tray off some huge feeders. Those little bitty no 8 conductors would have lit up like light bulbs!!!
 
Lord.

AND NOW, an annoying story from the old days

When I first got into HVAC, we got a call on a rooftop unit in downtown Spokane, "old OLD building." We had to remove the blower. But there is a PROBLEM

Many? most? rooftop units have a dedicated entry for the AC power, usually down low on the cabinet. For whatever reason --this one was installed long before codes got stiff or enforced-- the installer had come up through the roof with conduit, run it neatly right into the unit, BUT WAIT!!! there is no DISCONNECT!!

So they had mounted a nice big 3 pole (this was 3 phase) disconnect right on top of the cabinet RIGHT on top of the blower compartment, then run the three incoming hot wires from the entrance, up through the blower compartment to the disconnect, through the disconnect, and then run the three power feeds to the unit back down through the blower compartment--to tie in to the power entrance below it.

So when you remove the blower access panel you have SIX conductors running vertically from top to bottom RIGHT IN FRONT OF THE BLOWER. (sort of like a jail cell LOLOL)

So you pull the disconnect, you STILL have three wires that are HOT

Well, we go down below, we looked and looked, and asked anyone we found, and COUND NOT find whatever breaker/ fuse fed that circuit

Finally, we pulled the six "cold wires out of the way, then CAREFULLY, standing on a wood box, with plywood leaned up against the unit for insulation, ---one at a time, removed the "hot" wires and taped them off, then pulled them out of the way.........

Replaced the motor, serviced the unit, and put all the wires back.

At the time I even briefly came up with the bright idea, "let's throw a wrench across the switch, turn it on, and see what breaker trips"

IT TURNED OUT A FEW YEARS LATER that building suffered a little fire. And that AC circuit was a completely illegal "tap" in a wire tray off some huge feeders. Those little bitty no 8 conductors would have lit up like light bulbs!!!

Wow! I've never seen you post this one before. That's a goodun.
 
I have an electrical story. About 40 years ago, our firm was working on an air conditioning upgrade for an old middle school. The project Electrical Engineer was walking the site with us. Out in school yard, there was a concrete slab with a pad-locked metal door on it. The door led to some kind of electrical vault. My boss and the EE were older, so I climbed down into the vault with a flashlight. I can still remember my first words, "Jesus Christ!"

On the opposite wall, about 6' away, were three, horizontal, shiny copper bars (480V), totally bare and exposed with nothing in front of them. I felt very uncomfortable and stayed glued to the wall opposite the bus bars, and quickly got out of there. The EE said that installation was no longer legal, and he would replace it.

Can you imagine if some kids would have cut that lock, and gotten down into the vault?
 
I have an electrical story. About 40 years ago, our firm was working on an air conditioning upgrade for an old middle school. The project Electrical Engineer was walking the site with us. Out in school yard, there was a concrete slab with a pad-locked metal door on it. The door led to some kind of electrical vault. My boss and the EE were older, so I climbed down into the vault with a flashlight. I can still remember my first words, "Jesus Christ!"

On the opposite wall, about 6' away, were three, horizontal, shiny copper bars (480V), totally bare and exposed with nothing in front of them. I felt very uncomfortable and stayed glued to the wall opposite the bus bars, and quickly got out of there. The EE said that installation was no longer legal, and he would replace it.

Can you imagine if some kids would have cut that lock, and gotten down into the vault?

Fried little bastids.
 
I have an electrical story. About 40 years ago, our firm was working on an air conditioning upgrade for an old middle school. The project Electrical Engineer was walking the site with us. Out in school yard, there was a concrete slab with a pad-locked metal door on it. The door led to some kind of electrical vault. My boss and the EE were older, so I climbed down into the vault with a flashlight. I can still remember my first words, "Jesus Christ!"

On the opposite wall, about 6' away, were three, horizontal, shiny copper bars (480V), totally bare and exposed with nothing in front of them. I felt very uncomfortable and stayed glued to the wall opposite the bus bars, and quickly got out of there. The EE said that installation was no longer legal, and he would replace it.

Can you imagine if some kids would have cut that lock, and gotten down into the vault?

Around here there are several metal supply outfits with large traveling cranes. These are a huge cross beam that runs on tracks on the sides of the building, with a powered carriage that runs crosswise on the beam. How do they get their power? BY BARE MULTIPHASE BUSS BARS which have sliding? rolling? contacts. These bars run horizontally along one side of the building wall

Here's the thing. If some worker, "not thinking" was to lean a 20' piece of tube/ pipe/ material against the wall vertically in certain "accessable" spots, it could VERY easily contact those rails.

These work like third rail train/ subways, or overhead electric powered bus/ trolleys
 
............Which leads to..........

Accident Report Detail | Occupational Safety and Health Administration

At approximately 11:00 a.m. on February 22, 2002, Employee #1, the plant manager for Park Steel Co., a steel fabrication firm in Compton, CA, was performing electrical work on a bridge crane. He had observed an exposed busbar on the No. 2 overhead crane. Although the plant manager had no experience or knowledge of electrical work, he did not call an electrician in the interest of time. Instead, he decided to apply insulating black electrical tape to the exposed busbar himself. The exposed bus bar was located approximately 8 ft from the elevated platform used to service the crane. In order to reach the busbar, he brought a metal chair to stand on, asking Employee #2 to hold the chair so that it would not tip over while Employee #1 was insulating the busbar. While applying the black electrical tape to the exposed busbar, he contacted the energized bar which "grabbed" him and did not "let go". Employee #2 realized what was happening and so grabbed the employee by the waist with both arms and pulled him off. He could not support the weight of Employee #1, so Employee #1 approximately 11 ft 3.5 in. through an opening between a beam, located approximately 44 in. above the platform, and the platform floor. Emergency medical services were called, and Employee #1 was transported to Martin Luther King Hospital, where he was treated for his injuries and released five days later. The injuries to Employee #1 were a fractured pelvis, fractured coccyx, and dislocated right shoulder. Employee #2 received a minor burn on his left index finger. The casual factor leading to the accident was that Employee #1 was working in an energized system without following the procedures outlined in T.8 CCR 2320.2. Also, there were inadequate guardrails, allowing Employee #1 to fall off from the platform. Serious injuries would not have been sustained if there had been no fall from the platform through the opening between the beam and the platform floor.
 
............Which leads to..........

Accident Report Detail | Occupational Safety and Health Administration

At approximately 11:00 a.m. on February 22, 2002, Employee #1, the plant manager for Park Steel Co., a steel fabrication firm in Compton, CA, was performing electrical work on a bridge crane. He had observed an exposed busbar on the No. 2 overhead crane. Although the plant manager had no experience or knowledge of electrical work, he did not call an electrician in the interest of time. Instead, he decided to apply insulating black electrical tape to the exposed busbar himself. The exposed bus bar was located approximately 8 ft from the elevated platform used to service the crane. In order to reach the busbar, he brought a metal chair to stand on, asking Employee #2 to hold the chair so that it would not tip over while Employee #1 was insulating the busbar. While applying the black electrical tape to the exposed busbar, he contacted the energized bar which "grabbed" him and did not "let go". Employee #2 realized what was happening and so grabbed the employee by the waist with both arms and pulled him off. He could not support the weight of Employee #1, so Employee #1 approximately 11 ft 3.5 in. through an opening between a beam, located approximately 44 in. above the platform, and the platform floor. Emergency medical services were called, and Employee #1 was transported to Martin Luther King Hospital, where he was treated for his injuries and released five days later. The injuries to Employee #1 were a fractured pelvis, fractured coccyx, and dislocated right shoulder. Employee #2 received a minor burn on his left index finger. The casual factor leading to the accident was that Employee #1 was working in an energized system without following the procedures outlined in T.8 CCR 2320.2. Also, there were inadequate guardrails, allowing Employee #1 to fall off from the platform. Serious injuries would not have been sustained if there had been no fall from the platform through the opening between the beam and the platform floor.

Damn. Just DAMN!
 
That "tap" in the top photo is about what this would have been!!!
 
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