Poles Circuit Breaker
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 Square D SEF361600LSG 1600 Amp Circuit Breaker 3 Pole US $18,296.90 |
 New Square D SED364000LSGMR Circuit Breaker 4000 Amp 3 Pole  US $18,000.00
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 SQUARE D NHL361200 CIRCUIT BREAKER 1200 AMP 3 POLE NIB US $17,500.00
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 Cutler Hammer HND312T33W 1200amp 3pole circuit breaker US $3,800.00
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 NEW thlc436250 GE 250 Amp 600 V 3 Pole Circuit Breaker US $3,800.00
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 NEW thlc436350 GE 350 Amp 600 V 3 Pole Circuit Breaker US $3,800.00
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 GE TS TS203F 1400 AMP 3 POLE CIRCUIT BREAKER US $2,999.99
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 WESTINGHOUSE NB3800PF 3POLE 800AMP 600V CIRCUIT BREAKER US $2,999.95
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 ABB SACE F1H 1250A AMP CIRCUIT BREAKER 690V 3P POLE 800A AMP TRIP US $2,999.15
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 SIEMENS CIRCUIT BREAKER 800 AMP 600V 3 POLE SMD69800ANT US $2,500.00
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Protection of Electrical Installations
When speaking about the protection of electrical installation, the most often meant is the overcurrent protection. This is the protection that must be activated in case of exceedingly high currents in an installation (the currents whose value is higher than expected). It can be achieved using safety fuses, or (automatic) circuit breakers; there are two other names: LS and MCB switches.
The task of that protection is to switch out faulty circuits, and thereby protect the loads that are connected to those circuits, thus preventing the consequences (in the first place thermal overloading of conductors, and fire risk). In new buildings are in dwelling electrical installations almost exclusively used circuit breakers owing to their numerous advantages:
• simple use,
• multiple use (no replacement is needed after operation),
• smaller size,
• increased safety.
There is a large choice of circuit breakers by various manufacturers on the market. Their basic technical characteristics are:
• rated current,
• breaking characteristic,
• short-circuit capacity, etc.
The rated current value of the protection device must provide the best possible overcurrent protection of an installation.
When choosing the breaking characteristics, usually are available B, C and (sometimes) also D – complying with the IEC 60898 standard. For a residential installation the most often used is B characteristic. However, if loads with high starting current are to be connected to that installation, (e.g. angle grinders), C characteristics should be used, because it is more resistant to undesired switching-offs at the start.
The short-circuit capacity is declared by its maximum current. A circuit breaker (according to requirements of the standard) must be strong enough to break a circuit three times, and still preserve specific technical characteristics required.
The values, marked on the products, are: 3.000, 4.000, 6.000 and 10.000 A. It is true that usually in housing installation the actual short-circuit currents are lower. But for sure a circuit breaker which is able to break three times 6.000 A, can still more times break lower short-circuit current than a circuit breaker which is declared to be able to break three times 3.000 A. That's the reason why in some countries (e.g. Germany) the installation of circuit breakers with the short-circuit capacity under 6.000 A is not allowed; so one must be careful when choosing a circuit breaker, it isn't recommendable to choose circuit breakers having the lowest short-circuit capacity, which is, of course, the cheapest. In addition, neither should be ignored the quality sign on products (e.g. VDE, KEMA and the like), because it ensures the product has been submitted to an appropriate type test.
For single-phase circuits single-phase (single-pole) circuit breakers are used, and for three-phase circuits – three-pole circuit breakers that are specially produced and calibrated by the manufacturer. Therefore composition of three-pole circuit breakers using three single-pole devices is not an adequate solution, and "in the field composed" circuit breaker doesn't ensure all technical characteristics prescribed.
The second type of protection for an electric installation is protection against electric shock, i.e. against harmful effects of electric current on human body. Three levels of such a protection are known:
• protection against direct contact,
• protection against indirect contact,
• additional protection by using high-sensitive protection switches.
Since the safety is more and more important, for better protection of humans and animals and better fire safety is steadily being developed and perfected a third level – additional protection. The matter concerns the use of so-called residual current circuit breakers (old names for these protection devices are: current protection switches, FI & FID switches, and abbreviations RCCB, RCD). Additional protection for people and animals is enabled only by high-sensitivity protective switches of 30 mA or less. The protective switches with sensitivity of 100 mA are suitable only for fire protection, whereas protective switches with sensitivity of 300 or 500 mA are only convenient to be used as main protective switches.
The residual current circuit breakers are recommended wherever the risk of electric shock is increased: in bathrooms and other humid and wet rooms, nurseries and workshops, where portable electric tools are often used. Needless to say that their use is much expanded in hospitals, kindergartens and schools. The residual current circuit breakers can be used in all installation systems where null and protective conductors are separated. In old electrical installations where so-called nulling is still used such protective switches cannot be used.
Both types of protection: against overcurrent and against electric shock can be combined into one single protective device, named residual current circuit breaker with overcurrent protection (other names for this device: combined protective switch, FI/LS switch, RCBO). These devices include technical characteristics that are a combination of characteristics of both previous protective devices(rated current, breaking characteristic, short-circuit capacity, current sensitivity, etc.). By means of such a device a full-scale protection of electrical installations in a room can be achieved.
About the Author
How does a double pole circuit give you more power in a full breaker box?
I have a circuit breaker box which has no more empty spots, but I want to install washer dryer hook-ups. Some of the breakers are double pole, but some are single. I was told that I may be able to convert some of the singles to doubles in order to install the electric dryer. I am not an electrician, so I want to get a understanding of how this would work. Could someone help me to understand the difference between double and single pole and how I would be able to get additional power for the dryer? BTW, I am not going to try to install anything myself, I just like to be informed. Thanks for your help!
They are talking about 'piggy-back' breakers.
Assemblies of two circuit breakers that fit in one standard slot in your panel.
These are NOT the same as double pole breakers.
If can find them made for your type of panel you can get
'two circuits for the space of one', at the price of a decreased
'interrupting rating', which should be considered, but is rarely a
problem unless you're in a densely built-up area.
The washer will need a single pole breaker,
the dryer, likely a two pole if it's electrically heated.
If you're going to hire an electrician to do the work anyway, it will cost very little more to ask him to install an auxiliary 'load center' adjacent to your existing panel. It can have six poles easily enough so you've
got some spares to work with in future.
Double-Pole Circuit Breaker Lockout
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