Ground Fault Interrupter
Ground fault interrupters are designed to protect from electrical shock by interrupting a household circuit when there is a difference in the currents in the"hot" and neutral wires. Such a difference indicates that an abnormal diversion of current from the "hot" wire is occuring. Such a current might be flowing in the ground wire, such as a leakage current from a motor or from capacitors. More importantly, that current diversion may be occurring because a person has come into contact with the "hot" wire and is being shocked. When a circuit is functioning normally, all the return current from an appliance flows through the neutral wire, so the presence of a difference between "hot" and neutral currents represents a malfunction which in some circumstances could produce a dangerous or even lethal shock hazard.
The "hot" and neutral wires are passed through the sensing coil so that the currents in the two wires at any instant are traveling in opposite directions, giving a net zero current in the coil if the two currents are exactly equal. Since a current-carrying wire produces an AC magnetic field external to the wire, a non-zero current would induce a voltage in the sensing coil. The sensing coil is wound longitudinally to capture more of the wire's magnetic field and therefore be a more sensitive net current detector. Even so, the difference that it is supposed to detect is quite small. The GFI is designed to trip when there is more than 5 milliamperes of leakage current out of the normal pathway. The neutral return would then have 5 mA less current than the "hot" wire, but that might be out of a 20A load. So the circuit would have to detect a 0.025% deviation from 20A return current. Fortunately, comparator circuits such as anop-amp comparator are quite capable of detecting such differences. The voltage in the sensor coil is rectified and applied to the input of the sensitive comparator. The comparator activates a trip coil which opens both the "hot" and neutral wires. If all circuits were wired with correct polarity, opening the "hot" wire would be sufficient, but since it is not uncommon for them to be accidentally wired backward, it is prudent to interrupt both leads.
It is common household practice to wire several receptacles on a given circuit. A single GFI at the circuit panel will protect the entire collection of receptacles since a difference between "hot" and neutral current at any one of them will cause a difference at the GFI. A single GFI at one receptacle would not protect the entire circuit.
Because of the great sensitivity of the detection of current differences, GFIs are prone to nuisance tripping in certain applications. A rather common practice in some areas is to have a freezer on the carport, and carport receptacles are sometimes wired with GFIs. Under moist conditions you can sometimes get enough leakage current to trip the GFI, and persons come back to find their freezer thawed out. A necessary safety precaution in bathrooms and near pools, they are sometimes quite troublesome in outdoor applications where reliable power is needed. John de Armond has a good discussion of other circumstances which lead to nuisance tripping, particularly with campers and recreational vehicles.
for your philippine electrical concerns...needs...installation...orders...safeelectrical2013@gmail.com
METRO MANILA PHILIPPINES
WIRE AND CABLE SUPPLIER IN METRO MANILA
WIRE AND CABLE SUPPLIER IN QUEZON CITY
WIRE AND CABLE SUPPLIER IN LUZON
WIRE AND CABLE SUPPLIER IN VISAYA
WIRE AND CABLE SUPPLIER IN SUBIC
WIRE AND CABLE SUPPLIER IN CLARK
WIRE AND CABLE SUPPLIER IN THE PHILIPPINES
WIRE AND CABLE SUPPLIER IN THE PHILIPPINES
ELECTRICAL SUPPLIER IN METRO MANILA
ELECTRICAL SUPPLIER IN QUEZON CITY
ELECTRICAL SUPPLIER IN LUZON
ELECTRICAL SUPPLIER IN VISAYA
ELECTRICAL SUPPLIER IN SUBIC
ELECTRICAL SUPPLIER IN CLARK
ELECTRICAL SUPPLIER IN PHILIPPINE INDUSTRIAL PARK
ELECTRICAL SUPPLIER IN PHILIPPINE ECONOMIC ZONE
ELECTRICAL SUPPLIER FOR PHILIPPINE FOREIGNERS
ELECTRICAL SUPPLIER FOR PHILIPPINE PROVINCES
FOR YOUR PHILIPPINE ELECTRICAL CONCERNS...NEEDS...INSTALLATION...QUOTATION...ORDERS
KINDLY EMAIL US: SAFEELECTRICAL2013@GMAIL.COM
SAFEELECTRICALONLINE@GMAIL.COM
FOR YOUR PHILIPPINE ELECTRICAL CONCERNS...NEEDS...INSTALLATION...QUOTATION...ORDERS:
KINDLY EMAIL US: SAFEELECTRICAL2013@GMAIL.COM
SAFEELECTRICALONLINE@GMAIL.COM
FOR PHILIPPINE INQUIRIES LIKE LIGHTNING ARRESTER SUPPLY AND INSTALLATION
CONTACT US:
FOR PHILIPPINE INQUIRIES LIKE LIGHTNING ARRESTER SUPPLY AND INSTALLATION
CONTACT US:
FOR PHILIPPINE INQUIRIES LIKE LIGHTNING ARRESTER SUPPLY AND INSTALLATION
CONTACT US:
MOBILE NUMBERS: SMART: +63 09079522099
+63 09214026477
GLOBE: +63 09273919600
+63 09157920129
SUN: +63 9227192434
+63 09336253505
WIRELESS LANDLINE: +63 4068727
+63 4922566
LANDLINE: +63 4317553
HURRY..CALL US...NOW!!!!
THANK YOU FOR YOUR ORDERS AND INQUIRIES...
LIGHTNING ARRESTER SUPPLIER AND INSTALLER IN THE PHILIPPINES
ELECTRICAL FENCE SUPPLIER AND INSTALLER IN THE PHILIPPINES
LIGHTNING ARRESTER SUPPLIER AND INSTALLER IN METRO MANILA
ELECTRICAL FENCE SUPPLIER AND INSTALLER IN METRO MANILA
LIGHTNING ARRESTER SUPPLIER AND INSTALLER IN THE PHILIPPINE ECONOMIC ZONE
ELECTRICAL FENCE SUPPLIER AND INSTALLER IN THE PHILIPPINE ECONOMIC ZONE
LIGHTNING ARRESTER SUPPLIER AND INSTALLER IN THE VISAYA REGION
ELECTRICAL FENCE SUPPLIER AND INSTALLER IN THE VISAYAS REGION
LIGHTNING ARRESTER SUPPLIER AND INSTALLER IN THE MINDANAO
ELECTRICAL FENCE SUPPLIER AND INSTALLER IN THE MINDANAO
FOR YOUR LIGHTNING STRIKE PROTECTION...LET US HELP YOU AVOID SUCH ACCIDENTS...
BEFORE IT IS TOO LATE...BEFORE IT IS TOO LATE...
WHEN LIGHTNING STRIKE HIT YOU..
I GUARANTEE YOU..YOU'LL NEVER LIVE TO TELL YOUR EXPERIENCE...
DON'T BE THE NEXT VICTIM...PROTECT YOURSELF..YOUR FAMILY..YOUR BUSINESS AT ALL TIMES..
INSTALL A LIGHTNING ARRESTER IN YOUR PLACE...DO IT NOW BEFORE YOUR CAUGHT UNAWARE...
IF YOU HAVE LIGHTING PROTECTION INSTALLED...
YOU'LL HAVE PEACE OF MIND...YOU CAN SLEEP WELL EVEN WHEN LIGHTNING STRIKES...
YOU KNOW YOUR WELL PROTECTED...
IN YOUR HOME, IN YOUR PLACE OF BUSINESS AND IN YOUR PROPERTIES...
HURRY..CALL US...NOW!!!!
THANK YOU FOR YOUR ADVANCE ORDERS AND INQUIRIES...
"PHILIPPINE FOREIGNERS AND PHILIPPINE PROVINCES ELECTRICAL SUPPLIER
AND SERVICE PROVIDER"
"SAFE ELECTRICAL SUPPLY AND SERVICES"
No comments:
Post a Comment