Providing drilling services to oil and gas companies means that Saber Industries must frequently move its drill rigs from one site to another. That process is now safer and easier, since the company started using the Meltric Decontactor Series switch-rated motor plugs, which allow workers to safely make and break electrical connections, even under full load. They also provide the NEC-required “line of sight” disconnect.
Headquartered in Seminole, OK, Saber Industries, LP began operation in March, 2006 with the acquisition of several oil and gas drilling and service companies. The firm now operates eight rigs ranging from 7,700-12,000 ft. The rigs are moved frequently, typically every two weeks to a month. Each time a rig is moved, the motors, lights, heaters, washers, and other equipment must be disconnected and then reconnected at the new site. Connections sometimes must be broken during operation as well, for equipment maintenance or repairs.
Previously, the company used metal pin-and-sleeve connectors for 480 V circuits and 110-220 V single-phase circuits. Because of frequent washdowns, the pin-and-sleeve connectors posed some safety problems.
“When the plugs were washed down, water got into one of them, and it blew apart,” explains assistant drilling supervisor Joe Morgan. “If someone had touched it while standing on wet ground, he could have been killed.” Morgan adds that the contacts on the connectors often welded together, making it necessary to replace them. “They are expensive to replace,” he notes, “and because you can’t replace parts, you end up buying a whole new device.”
Decontactors Keep the Rigs Running
About a year ago, the company began replacing the connectors with Meltric Decontactors, which are now installed on its three largest rigs. Electrician Ryan Liebschwager reports that there have been no problems with contacts welding together, and motors can now be disconnected under load if necessary.
The Decontactors incorporate spring-loaded, silver-nickel butt-style contacts that provide consistently superior electrical performance over thousands of operations and are resistant to wear, corrosion, oxidation, and other factors that contributed to premature failure of the pin-and-sleeve-type devices. In some cases, they are actually used as a “line of sight” disconnect switch, particularly for low-voltage applications such as fuel pumps.
“If I need to work on a fuel pump,” Liebschwager explains, “I can disconnect it so it is turned off and then keep the Decontactor in sight so someone doesn’t turn it back on while I am working on it.” With Decontactors, provisions for locking out the plug are standard so only a lock and tag are needed to comply with lockout/tagout requirements.
Disconnecting a motor is a simple operation, initiated by pressing a pawl on the Decontactor, which breaks the circuit and ejects the plug to its rest position. Then, a simple quarter-turn of the plug allows it to be totally withdrawn from the receptacle in complete safety, since the circuit is already dead. When the plug and receptacle are separated, a safety shutter prevents access to live parts.
The company uses the Decontactors on motors ranging from 7-1/2 to 60 hp, as well as on all other electrical equipment.
“We use 18 circuits for low-voltage and 30 for high-voltage, and they break in multiple places, so there are a lot of Decontactors on a rig,” Morgan says.
Holding Up in Harsh Conditions
Operating conditions can be severe. “They get covered with mud and water, and even ice in winter,” Morgan points out. “They are inaccessible when the rig is running, so we depend on them to stay in working condition.” Since the rigs operate around the clock, shutdowns can cause serious losses.
Durability of the non-metallic Decontactor housing has been proven on the jobsite. Morgan recalls an incident where one unit fell between a truck and some equipment that was being moved.
“The plug was caught between them,” he says. “When the truck pulled away, the housing flexed back to its original shape, and we were able to continue using it until we got a replacement.”
According to Liebschwager, the color-coded terminals on the Decontactors simplify his job. “With some pin-and-sleeve devices, the terminals are numbered, but you never know how the electrician set them up,” he explains. “Then you have to take them apart to find out. With the color-coding, you always know which one goes where.”
The Decontactors cost less than the previous connectors, and their modular construction is an advantage as well. Liebschwager says he also likes the way their water-tight rubber gaskets are packaged to fit different cable sizes: “The way they are put together, you can’t lose them.”
Another Decontactor feature that has been useful in some applications is the factory’s ability to configure the contact arrangement so that it will only connect with a designated receptacle. This is useful where a misconnection could have unintended consequences.
Morgan says the company is pleased with the performance of the Decontactors on the three rigs where they are installed and is looking into converting the other rigs as time permits.