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1870 S. Acoma Street  Denver, CO 80223

Phone (303) 777-2428          Fax (303) 778-1939

Metro Inspectors Utility Hook Up Calc. w/ Ohm's Law Calc. Voltage Drop Conduit Fill Table

 

CALCULATING WITH OHM'S LAW

A. When Volts and OHMS are known:

Amperes = Volts
---------
OHMS		 of I = E
-----
R

Example: Find the current of a 120 volt circuit with a resistance of 60 OHMS.

 

I = E
-----
R		 = 120
------
60		 = 2 Amperes

B. When Watts and Volts are known:

Amperes = Watts
----------
Volts		 or I = P
------
E

Example: A 120 Volt Circuit has a 1440 Watt Load. Determine the current.

I = P
---------
E		 = 1440
---------
120		 =12 Amperes

C. When OHMS and Watts are known:

Example: A circuit consumes 625 watts through a 12.75 OHM resistor. Determine the current.

Notes:
A. One Electrical Horsepower = 746 watts. Electric Motors are rated in horsepower.
B. One kilowatt = 1000 watts. Generators are rated in kilowatts.

 

Last modified: September 24, 2008