SAMLEX AMERICA INC. | 9
Power Factor, (PF):
It is denoted by “PF” and is equal to the ratio of the Active Power
1JO8BUUTUPUIF"QQBSFOU1PXFS 4JO7"5IFNBYJNVNWBMVFJTGPSSFTJTUJWFUZQFT
of loads where the Active Power (P) in Watts = the Apparent Power (S) in VA. It is 0 for
purely inductive or purely capacitive loads. Practically, the loads will be a combination of
SFTJTUJWFJOEVDUJWFBOEDBQBDJUJWFFMFNFOUTBOEIFODFJUTWBMVFXJMMCF/PSNBMMZ
it ranges from 0.5 to 0.8 e.g. (i) AC motors (0.4 to 0.8), (ii) Transformers (0.8) (iii) AC to
%$4XJUDI.PEF1PXFS4VQQMJFT UPFUD
Load:
Electrical appliance or device to which an electrical voltage is fed.
Linear Load:
A load that draws sinusoidal current when a sinusoidal voltage is fed to it.
&YBNQMFTBSFJODBOEFTDFOUMBNQIFBUFSFMFDUSJDNPUPSFUD
Non-Linear Load:
A load that does not draw a sinusoidal current when a sinusoidal volt-
BHFJTGFEUPJU'PSFYBNQMFOPOQPXFSGBDUPSDPSSFDUFE4XJUDIFE.PEF1PXFS4VQQMJFT
(SMPS) used in computers, audio video equipment, battery chargers, etc.
Resistive Load:
"EFWJDFPSBQQMJBODFUIBUDPOTJTUTPGQVSFSFTJTUBODF MJLFåMBNFOU
MBNQTDPPLUPQTUPBTUFSDPGGFFNBLFSFUDBOEESBXTPOMZ"DUJWF1PXFS 8BUUTGSPN
the inverter. The inverter can be sized based on the Active Power rating (Watts) of
SFTJTUJWFUZQFPGMPBETXJUIPVUDSFBUJOHPWFSMPBE FYDFQUGPSSFTJTUJWFUZQFPGMPBETXJUI
5VOHTUFOCBTFEIFBUJOHFMFNFOUMJLFJO*ODBOEFTDFOU-JHIU#VMCT2VBSU[)BMPHFO-JHIUT
BOE2VBSU[)BMPHFO*OGSBSFE)FBUFST5IFTFSFRVJSFIJHIFSTUBSUJOHTVSHFQPXFSEVFUP
lower resistance value when the heating element is cold).
Reactive Load:
A device or appliance that consists of a combination of resistive, inductive
BOEDBQBDJUJWFFMFNFOUT MJLFNPUPSESJWFOUPPMTSFGSJHFSBUJPODPNQSFTTPSTNJDSPXBWFT
DPNQVUFSTBVEJPWJEFPFUD5IF1PXFS'BDUPSPGUIJTUZQFPGMPBEJTFH"$NPUPST
1'UP5SBOTGPSNFST 1'"$UP%$4XJUDI.PEF1PXFS4VQQMJFT 1'
UPFUD5IFTFEFWJDFTSFRVJSF"QQBSFOU1PXFS 7"GSPNUIF"$QPXFSTPVSDF5IF
Apparent Power is a vectorial sum of Active Power (Watts) and Reactive Power (VAR).
The AC power source has to be sized based on the higher Apparent Power (VA) and also
based on the Starting Surge Power.
SECTION 2 |
General Information
