Safe, Economical, and Reliable Standard Duty Devices
MELTRIC Standard Duty plugs and receptacles provide a more economical alternative for applications where the added benefits of Switch-Rated devices are not required. Because they are based on the same technology used in our Switch-Rated products, users are ensured of safe and reliable operation over thousands of operations.
Please consult the High Ampacity product section for applications above 250A.
Benefits
User Safety
Like all MELTRIC devices, our Standard Duty plugs and receptacles are designed with the first priority of keeping users safe, even in abnormal conditions. More…
Ease of Operation
Integral and optional features make connection and disconnection easier than with competitive devices, even in cord drop and in-line applications. More…
Improved Reliability
Spring-loaded silver-nickel butt contacts maintain high conductivity for thousands of operations, even in harsh conditions. More…
Life Cycle Cost Reduction
Reduce equipment, installation, maintenance, and operational costs. More…
Spring-Loaded Butt Contacts Provide for Thousands of Consistent and Reliable Connections
MELTRIC Standard Duty plugs and receptacles use spring-loaded, butt-style contacts similar to those used on contactors and switchgear. Their end-to-end mating provides a stable connection, the spring-loading delivers optimal contact pressure, and the integrity of the electrical connection is maintained over thousands of operations.
Spring-loaded butt contacts automatically compensate for manufacturing variations, eliminating contact mating and connection quality problems caused by the dimensional variations of other contact designs.
End-to-end mating eliminates the effects of wear inherent with sliding contacts.
Consistent spring pressure eliminates overheating caused by poor contact force.
The performance and design advantages of spring-loaded butt contacts make them a superior choice for providing consistently safe and reliable connections.
Silver-Nickel Contact Material Provides Superior Conductivity
MELTRIC uses solid silver-nickel contact surfaces on its Standard Duty plugs and receptacles. The contacts’ 85% silver and 15% nickel composition combines the durability of nickel with the excellent conducting properties of silver.
Silver-nickel contacts provide significant advantages over the brass materials used on most other types of plugs and receptacles:
Silver-nickel maintains low contact resistance and superior electrical properties even after oxidation and tarnishing.
Silver-nickel withstands arcing very well and only welds at extremely high pressure and temperature.
The hardness of nickel gives the silver-nickel contacts excellent wear resistance.
Silver-nickel performs well in and withstands wet and corrosive environments.
The combination of silver-nickel contacts with a spring-loaded butt-style design provides a long service life with no degradation of conductivity and easily withstands repetitive making and breaking of connections.
MELTRIC uses a spring-loaded ejection system to provide a quick and secure separation of the contacts during disconnection of the circuit. The quick break mechanism drives the contacts open in 15 ms or less, minimizing internal arcing and its impact on the contacts, should the device be operated under load.
There is no struggling to remove the plug from the receptacle on MELTRIC DR Series devices. Once the circuit has been deenergized, pressing the release button automatically disengages the contacts and ejects the plug to the rest position. The plug can then safely be removed by rotating it 30° counterclockwise and withdrawing it.
Dead Front Eliminates Hazards Posed by Exposure to Live Parts or Arcing
Most standard plugs and receptacles are not intended to be disconnected under load and drawing an arc during plug removal is an inherent hazard when traditional pin and sleeve and twist-type devices are accidently disconnected under load. While most MELTRIC DR Series Standard Duty devices are also not intended to be disconnected under load, the making and breaking of the contacts is isolated in an enclosed arc chamber, so if they are inadvertently disconnected under load, the plug contacts are deenergized and separated from live parts before the plug can be physically removed.
When the DR receptacle’s release button is pushed, its spring-loaded operating mechanism instantly opens the contacts to break the circuit and ejects the plug to rest position. The quick (15 milliseconds) breaking of the contacts minimizes the arcing that will result if the device is accidently disconnected under load. Any arcing that does occur is safely contained within the internal and enclosed arc chamber.
In the rest position, the plug contacts are dead and separated from live parts by a safe distance. Isolated and inaccessible to users, all contacts are still fully contained within an enclosure formed by the plug’s skirted casing and the receptacle’s casing.
The rotation of the plug required prior to its removal from the receptacle automatically closes and locks the safety shutter on the receptacle. This ensures that potential arc paths and access to live parts are blocked before the plug can be removed. There is no possibility of drawing an arc.
All DR Series devices include standard provisions on the plug that allow users to perform lockout/tagout by simply inserting a lock (or hasp) through an existing hole on the device. The user only needs to provide the lock–no additional mechanisms are required.
Simple lockout provisions for the receptacle are also provided as an option on both the DR and PN Series. An available locking pin fits snugly in a circular opening through the pawl and prevents the pawl from operating. Various size locks and lockout hasps can be used with the locking pin to complete the lockout.
The receptacle lockout provision is primarily used to lock the lid in the closed position so that a plug may not be inserted. On the DR Series, this feature can also be used to lock the plug and receptacle together to prevent unauthorized or accidental disconnections.
Spring-Assisted Terminals Provide Superior Conductor Connections
On traditional plugs and receptacles, the loosening of terminal screws is a common cause of failure. MELTRIC devices have patented, spring-assisted terminals that provide more permanent and secure conductor connections.
As the terminal screw is tightened, pressure is generated against the conductor and causes the split-terminal body to expand and elliptically deform the spring ring around the terminal. Since the spring ring wants to return to its original circular shape, it exerts a constant pressure against the terminal conductor, pushing them together. This constant spring pressure on the screw and conductor helps to compensate for strand settlement and conductor yield, while providing superior resistance to the effects of vibration, shock, and thermal cycling.
MELTRIC DR Series plugs and receptacles are available with optional auxiliary contacts that allow users the convenience and flexibility of controlling auxiliary equipment, monitoring process parameters, and/or communicating alarms without the need for secondary connectors. The larger models are available with up to 6 auxiliary contacts.
MELTRIC PN and DR Series plugs and receptacles achieve their rated watertightness simply by connecting the plug and receptacle. There is no need to thread on or turn additional watertightness rings as is required on many pin and sleeve devices.
PN Series devices are available in either Type 4X or Type 3R configurations. The DR Series provides Type 3R protection as standard and Type 4X as an option.
MELTRIC provides a wide variety of mounting angles, handles and wall boxes, allowing its devices to be used in wall box receptacle, in-line, direct motor mounted, panel mounted, cord drop, flexible conduit, and other applications. This makes it easy to locate a plug and play connection anywhere it is helpful.
We also offer standard and custom-made adapter plates to simplify retrofits by allowing MELTRIC receptacles to be mounted on existing wall boxes.
MELTRIC plugs and receptacles are durable and withstand harsh environments, so repairs may never be necessary, but if they are, replacement parts are reasonably priced and readily available. The design allows the changeout of casings, individual contacts, full interiors, or other specific parts, avoiding the need and cost of replacing the entire device.
It should be noted that only devices returned to the factory for rebuild will maintain their UL/CSA certification; devices that are field repaired by users do not.
