To describe the voltage drop of street lighting.Full description
calculo de caída de tensionDescripción completa
Voltage DropFull description
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To describe the voltage drop of street lighting.
excel calculator
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Voltage drop for common wire sizes for common currents encountered in instrumentation.
one can choose the power cable for a specied rated motor in this format....after that it will give the voltage dropFull description
In this guide, a design engineer works on a converter drive design and determines the voltage change coefficient during the drive start, compares it to permissible levels and suggests solutions to ...
In this guide, a design engineer works on a converter drive design and determines the voltage change coefficient during the drive start, compares it to permissible levels and suggests solutions to ...
In this guide, a design engineer works on a converter drive design and determines the voltage change coefficient during the drive start, compares it to permissible levels and suggests solutions to ...Full description
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electrical power cable sizing based on ampacity, fault level, voltage drop for lighting motorized load indian database. motor cable sizing,Full description
This tool help you to calculate voltage drop in cableFull description
VOLTAGE DROP CALCULATIONS FOR TRANSFORMER
i)
TRANSFORMER DETAILS : ‐
Transformer No: Location
XXXXXXXX On Ground Pi
MVA
Voltage HT side :
PCC VHT
KV
Voltage LT side :
VLT
KV
Base MVA
PB
MVA
Fault Current
IF
KA
Rated LT System Voltage
VR
V
Transformer capacity Connected Load
Base Impedence
ZB=(VR)²/(PB)
Per phase LT voltage ( VPH )
VPH=VR/1.732 Xi
%Impedence of transformer of transformer (P i MVA)
ZPU=Xi * (PB/Pi)
P.U. Impedance of Transformer of Transformer for Base MVA(P ᵣ MVA) ii)
V
BIGGEST MOTOR DETAILS : ‐
Consider The Biggest Motor in PCC is Pump (W M KW). The Method of Starting of Starting is through Soft Starter, starting current shall be 3 times the Full Load Current at Power Factor COSφ. WM
KW
(WM*10³)/(1.732*COSφFL*VR)
A
Soft Starting 3* IMFL
A
Motor KW Rating Motor Full Load Current (IMFL) Method of Starting of Starting Motor Starting Current (I MST) Motor Connection Cable No. Of Runs Of Runs
mm²
Cable Resistance
D N RC
Ω/KM
Cable Reactance
XC
Ω/KM
Cable Length ( Approx)
L
KM
ZB*ZPU
Ω
Resistance of Motor of Motor Feeder Cable R C
( RC*L)/N
Ω
Reactance of Motor of Motor Feeder Cable X C
( XC*L)/N
Ω
iii) VOLTAGE DROP CALCULATION : ‐ Transformer Impedance X TR
iv) CALCULATION OF VOLTAGE DROP AT MOTOR TERMINALS (V MS) : ‐ The allowable Voltage drop at motor terminals shall be 15%. Formula used is VPH² = (VMS*COSφST+IMST*RC)²+(VMS*SINφST+IMST*XC+IMST*XTR)² On Simplification, VPH² = (VMS² + IMST²*(RC²+XC²+XTR²+2*XC*XTR) + 2* IMST * VMS ( RC COSφST+ XC SINφST+XTR SINφST)
Where, VMS ‐ Voltage at Motor Terminals IMST ‐ Motor Starting Current VPH ‐ Per phase voltage % Voltage drop at Motor Terminals = v)
((VPH‐VMS)/VPH)*100
CALCULATION OF VOLTAGE AT BUS (V BS) : ‐
The Allowable Voltage drop at PCC Bus shall be 10%. Formula used is 2
VBS = (VMS*COSφST+IMST*RC)²+(VMS*SINφST+IMST*XC)² % Voltage drop at Bus =
((VPH‐VBS )/VPH)*100
Vi) CALCULATION FOR MOMENTARY OVERLOADING : ‐ The Momentary Over‐Loading on the transformer is considered as a Condition When the Biggest Motor is Started while all the other loads in the PCC are working. In this Case, the Total Current (Biggest Motor Starting Current + Base Current) shall not exceed 150 % of the FLC of the Transformer. Transformer Capacity
Pi
MVA
Transformer Full Load Current
ITFL
A
Largest Motor Rating
WM
Kw
Full Load Power Factor
CosφFL
Starting Power Factor
CosφST WM/COSφFL
KVA
PBTR
KVA
PBTR ‐ (WL/COSφFL)
KVA
[PBTR ‐ (WL/COSφFL)]/(1.732*VR)
A
IMST
A
KVA Requirement for largest rating motor Total Base Load of Transformer Base KVA Without Biggest Motor Base KVA current without biggest motor I BTR Biggest Motor Starting Current Total current
=
(I BTR CosφFL + IMST CosφST) + j (I BTR SinφFL + IMST SinφST)
150% FLC of transformer
1.5*IFTR
A A
The Total Current (Sum of Base Current and Biggest Motor Starting Current) has to be below 1.5 times the Full Load Current of Pi MVA Transformer. Therefore, WM KW Motor can be started using this Transformer. vii) The capacity of the Transformer selected Pi MVA is in order as it fulfills the following conditions: 1 2 3
The voltage drop at Motor Terminals is within the permissible limit of 15%. The voltage drop at Bus Terminals is within the permissible limit of 10%. The Total Current (Sum of Base Current and Biggest Motor Starting Current) is below 1.5 times the Full Load Current of Pi MVA Transformer.
