Siemens Circuit Breaker Expands Design Possibilities

Siemens 3VA Molded Case Circuit Breakers

A circuit breaker such as the Siemens new 3VA molded case circuit breaker line is an essential piece of safety equipment that protects critical infrastructure from the harmful effects of short circuits and overloads.

MCCBs rank among the most important safety components in low voltage power distribution.  An estimated 30 million MCCBs are installed each year around the globe.

Siemens 3VA5 molded case circuit breaker.

The new UL-certified series of 3VA molded case circuit breakers from Siemens was designed for low-voltage power distribution in buildings, infrastructure, and industrial applications. But the line was not just designed to protect devices today, but to grow as applications demand and needs change.

Siemens 3va electrical circuit breaker line is built around a modular concept with a variety of models and accessories.

Steiner Electric has placed in inventory Siemens 3VA products that meets the needs of Chicago-area contractors, electricians, MROs, OEM personnel and more.

The 3VA Family

This wide-ranging list of devices include multiple circuit breaker types, auxiliary switches and alarms, a variety of trip options, and the lugs and wire connectors that keep it all together.

 

Siemens 3VA5 circuit breakers are available in 125 A and 250 A
Siemens 3VA5 circuit breakers are available in 125 A and 250 A frames with a variety of options for each.

Steiner offers these breaker boxes based on two Siemens 3VA5 frame families.

  • The 125 A frame is a 3-pole breaker box with 25 kA @ 480 V interruption rating that come in models that trip at 15 A, 20 A, 50 A, 100 A, and 125 A.
  • The 250 A frame has a 35kA @480 V interruption rating, and trip circuits are rated at 150 A, 200 A, 225 A, and 250 A.

Both devices require minimum space because of their compact design. The footprint for the 3VA5 125 A frame model is 3 in. by 3.8 x 5.5 in. and the footprint for the 250 A frame is 4.13 in. x 4.21 x 7.28 in.

Safe Tripping

For safe operation, the 3VA5 Siemens circuit breakers are based on the concept of thermal magnetic trip units (TMTUs). These TMTUs are two separate tripping mechanisms – thermal and magnetic—that are built into the same device.

In a thermal-magnetic circuit breaker, the trip unit includes elements designed to sense the heat resulting from an overload condition and the high current resulting from a short circuit.

The thermal safety component works on thermal inverse-time, meaning the higher the current, the faster the breaker trips. The thermal element is a bimetallic strip, which means it has two different metals bonded together that have different thermal expansion characteristics. As that strip warms up, the thermal differences cause the metals to twist and bend and eventually contact a trip bar causing the contacts to spring open.

The second safety component is the magnetic trip. The circuit breaker has a trip unit that senses a magnetic field generated by current to detect a short circuit. This type of circuit breaker trips immediately when a short circuit occurs, but delays an appropriate amount of time before tripping in the event of an overload.

Array of Design Options

Steiner offers a wide range of Siemens’ internal accessories that can fit in any of the 3VA products. They can be adapted flexibly, quickly and easily to individual specifications. Color coded for simple installation process, they are designed to always be installed at the correct position in the circuit breaker.

A door mounted rotary operator. Just one of the many options available from Steiner.
A door mounted rotary operator. Just one of the many options available from Steiner.

Accessories include multiple operator options, including door mounted rotary operators that come either with illumination, which provides a clear indication of the switching position, and without an illuminating kit.

Also available is the Max Flex flange mount operating system that allows the user to locate the circuit breaker almost anywhere within an enclosure. It uses a flexible cable that connects to a breaker operator mechanism and a handle located on the enclosure’s flange.

Also available are auxiliary and alarm switches that can be integrated with all sizes of Siemens breakers. The switches snap for easy installation and to swap out as needs change.

3VA9, UL, UVR undervoltage release
The Siemens 3VA9, undervoltage release switch.

Auxiliary switches can be used to operate indicator lights, relays or other accessories to provide the breaker’s status. Alarm switches indicate that the circuit breaker has tripped due to an overload, short circuit or ground fault. A shunt trip will trip a breaker remotely, and an under voltage trip release will activate when voltage shuts off or dips.

So, when looking to install new or replacement breakers, consider the 3VA5 products that offer myriad design possibilities.

Hubbell Disconnect Switch Enhances Safety with LED Phase Indicators

Hubbell Insight Circuit Lock with LEDs

The National Electronic Code requires that disconnect switches be in the line of sight of a user, motor and the equipment the motor drives. This allows the motor to be shut down for maximum safety. Now, Hubbell Wiring Device-Kellems has upgraded its 30amp disconnect switches to include LED lights that takes this line-of-sight visibility to the next level.

The company has introduced technology, dubbed inSIGHT™, that incorporates six LED phase-indicator lights. Three LEDS show the status of the line side and three lights represent the load side wiring. The electrical status of each phase is within sight and clearly displayed on the cover so that users are provided a secondary way to confirm make/break on all phases prior to removing the enclosure cover. For example, if there is a welded contact or dropped phase the operator can determine that a problem exists (see Fig. 1).

Hubbell non-metallic disconnect switch with LED lights

With an ever growing focus on safety improvements, Hubbell disconnects provide a difference you literally can see.

Hubbell phase-indicating disconnect switches are available in non-metallic, and stainless steel square top and sloped top versions. Replacement covers are available for upgrades to existing installations.

LED lights from Hubbell Wiring
Fig. 1: LED lights provide users with the status during different phases of line and load wiring.

The 30A Circuit-Lock Disconnect Switches are available with or without a jog switch to slowly move the motor forward or in reverse. Customers have the option to either purchase the entire disconnect unit or an LED replacement cover for compatible existing 30A Disconnect Switches.

As with most NEC-certified disconnect switches, when locked in the “off” position, the high-visibility red rotary handle complies with OSHA lockout/tagout requirements. When in the “on” position, the cover cannot be opened.

Hubbell's stainless steel sloped top disconnect.
Hubbell’s stainless steel sloped top disconnect

Designed to be tough, reliable and provide exceptional performance in the most grueling conditions, the disconnect switch’s IP69k rating means that it can withstand high-pressure, high-temperature washdowns. The units have been tested to withstand extremely hot water (176degF) and high-pressure water spray (1450psi) from various angles. In other destructive testing, the device is placed in a dust chamber for 8 hours while a vacuum attempts to pull dust into the sealed housing.

HHubbell's stainless steel square top disconnect.
Hubbell’s stainless steel square top disconnect

The switch is also certified by the NSF for use in food processing applications, and is UL Listed for Type 4X, which means that it can be used for either indoor or outdoor applications. It is also listed for Type 12 enclosures, which are enclosures constructed without knockouts for indoor use to protect personnel against access to hazardous parts, and to provide ingress protection for the electrical contents.

Features:
* Six highly visible integral phase identification LEDs
* External LEDs provide secondary means of visual confirmation of make/break on all phases
* Cover cannot be removed with switch in the “ON” position
* Certified by NSF for hygiene in Food Processing applications
* Highly visible red handle which meets OSHA LO/TO capabilities
* Available in 30 Amp non-metallic and stainless steel versions, with or without JOG switch
* UL witnessed IP69k and UL Type 4X and 12 Environmental ratings

 

Square D Road Warrior Trailer Rolls Into Steiner Electric

Industry leader Square D loaded up its new Road Warrior Trailer with some of its newest and most innovative products and is making appearances at three Steiner Electric branches in August.

From ready-to-install (RTI) panelboards to surge protection devices with myriad mounting options, meters, diagnostic devices and energy management systems, the products on display in the Square D Road Warrior Trailer are designed to speed-up installations, reduce mistakes, call backs and component lists.

The Road Warrior Trailer makes three stops at Steiner Electric in August. The first is Aug. 8, from 11am to 1pm, in Elk Grove Village. On Aug. 15, the trailer rolls into Rockford, and two days later it appears at the St. Charles branch from 10am to 1pm.

Units on display include ready-to-install (RTI) panelboards such as the NQ panel, which is designed to meet 240Vac maximum rating applications and offer powerful circuit protection. Additional features showcased include a group mounted (factory installed) SPD unit, finger guard on incoming wires as per new code, and CAFI and DF breakers.

Another line on display is the the HomeLine Plug-on group of circuit breakers and load centers that help contractors save time on installation, and meet NECs code regarding arc and ground fault requirements.

Homeline Plug-on features on display include, Plug on Neutral CAFI and DF breakers, incoming wires finger guard, push-to-test DF breakers, and Group mounted SPD.

Also on display is the QO load center for applications ranging from agricultural to industrial, commercial to residential with indoor and outdoor versions available. The QO is a load center and circuit breaker family that comes in single and three-phase, ¾ in. circuit breaker width, 30  to 400 amps, 2 to 42 circuits and separate flush or surface mounted covers.

Additional features on display for the QO Load Center (Plug on), include the finger guard requirement, Plug on Neutral CAFI and DF breakers, the Qwik Grip wire management system, hinged Trim with adjustable dead front, and Visi-Trip breakers.

Other items on display include EZM corner section metering, Wiser Energy Load Center, which features a new load control with all-inclusive CT’s and communication package for metering, and a whole range of SPDs in unit mount, group mount and side mount.

Come See The Square D Road Warrior Trailer in August
• Elk Grove on Tuesday, Aug. 8, from 11am to 1pm
• Rockford Branch, on Tuesday, Aug. 15, from 11am top 1pm
• St. Charles on Tuesday, Aug. 17, from 10am to 1pm
Lunch provided during each event.

The Circuit Breaker

A circuit breaker is one of the most important safety devices in your home, but most people don’t give them much thought until their lights go off or they can’t watch TV because the breaker has tripped.  When the electrical wiring in a building has too much current flowing through it, the breaker cuts the power.

But do you know how old the circuit breaker is?

Circuit Breaker Steiner Electric Continue reading “The Circuit Breaker”

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-By Ron Styne

People wonder how the price of copper and steel are determined because those levels have such an impact on many of the products sold in both the electrical and industrial industries. The price on metals is determined by the London Metal Exchange (LME).London Metal Exchange Continue reading “What is the London Metals Exchange?”