Calculated Industries ElectriCalc Pro User manual

User'sGUide — 1
TABLE OF CONTENTS
ELECTRICALC®PRO..........................................................................3
GETTING STARTED............................................................................4
KEY DEFINITIONS.................................................................................4
Basic Function Keys ..........................................................................4
Mode Set-up Keys ..............................................................................5
Electrical Keys ....................................................................................6
Motor Keys..........................................................................................8
Wire Sizing Keys.................................................................................9
Voltage Drop Keys ............................................................................ 11
Grounding Conductor Keys...............................................................12
Fuse/Breaker Keys ...........................................................................13
Conduit Sizing Keys..........................................................................15
PREFERENCE SETTINGS ..................................................................18
BASIC MATH OPERATIONS..........................................................19
PERCENT CALCULATIONS ..........................................................19
MEMORY OPERATIONS .....................................................................19
Using M+...........................................................................................20
Using Memory Storage Keys (M1- M9).............................................20
USING THE ELECTRICALC PRO ....................................................21
KIRCHHOFF’S LAW.............................................................................21
Finding Voltage .................................................................................21
Finding Amps ....................................................................................22
Finding Current Load ........................................................................22
Finding Amps From Kilowatts ...........................................................23
Finding Volt-Amps.............................................................................23
Finding kVA Rating ...........................................................................24
Finding Wattage ...............................................................................24
Finding kW Rating ............................................................................25
OHM’S LAW .........................................................................................26
Finding Volts .....................................................................................26
Finding Amps ....................................................................................26
Finding Resistance (Ohms) ..............................................................27
MOTOR FUNCTIONS ..........................................................................27
Finding Single-Phase Full-Load Current...........................................28
Finding Motor Wire Size and Ampacity.............................................28
Finding Synchronous Motor Horsepower..........................................29
Finding Direct Current Motor Horsepower ........................................30
(cont’d)

2 — electricalc®Pro
AMPACITY WIRE SIZING ....................................................................30
Wire Sizing Based on Insulation Rating............................................31
Re-Sizing Wire Based on Different Insulation Ratings......................32
Wire Sizing Based on Ambient Temperature ....................................32
Wire Sizing Based on Material Type .................................................34
Sizing Parallel Conductors................................................................35
Finding Derated Wire Size................................................................36
Sizing Temperature-Adjusted Derated Wires....................................36
VOLTAGE DROP..................................................................................38
Finding Single-Phase Voltage Drop..................................................38
Finding Three-Phase Voltage Drop...................................................39
Finding Voltage Drop Wire Size........................................................40
Finding Voltage Drop Distance .........................................................41
Finding Voltage Drop Resistance......................................................43
GROUND CONDUCTOR WIRE SIZE..................................................44
EQUIPMENT GROUNDING COUNDUCTOR WIRE SIZE...................45
FUSE AND CIRCUIT BREAKER SIZE .................................................45
STARTER SIZE ....................................................................................47
OVERLOAD PROTECTION SIZE ........................................................47
CONDUIT SIZE ....................................................................................48
Finding Motor Branch-Circuit Wire Size and Conduit Size —
Same Wire Type and Size ................................................................49
Finding Conduit Sizes For Multiple Conductors —
Same Wire Type and Size ................................................................50
Finding Number of Wires in Existing Conduit —
Same Size, Various Types ..............................................................51
Finding Conduit Size —
Multiple Conductors, Different Wire Sizes and Types.......................52
CONVERTING KILOWATT-HOUR AND BTU.......................................53
PARALLEL RESISTANCE ....................................................................54
APPENDIX A — DEFAULT SETTINGS.............................................55
APPENDIX B — PREFERENCE SETTINGS ....................................56
APPENDIX C — 2011 NEC REFERENCES ......................................57
APPENDIX D — CARE INSTRUCTIONS..........................................57
APPENDIX E — ACCURACY/ERRORS,
AUTO SHUT-OFF, BATTERIES, RESET...........................................58
REPAIR AND RETURN......................................................................60
WARRANTY.......................................................................................61
(cont’d)

User'sGUide — 3
ELECTRICALC®PRO
The ElectriCalc®Pro is an invaluable calculator for today’s busy
electrical professional. Unlike a regular calculator, it has intuitively
labeled “electrical keys” and conforms to the 2011 (and 2008, 2005,
2002, 1999, 1996) and future National Electrical Codes, allowing you
to solve Code-related problems quickly and accurately. The most
common NEC tables are now at your ngertips!
An important feature of the ElectriCalc®Pro is that it is programmed
to accept future NEC changes, allowing you to conveniently install
future Code editions in a few simple steps.
The ElectriCalc®Pro instantly solves for:
• Kirchhoff’s Law
• Ohm’s Law
• Volts, Amps, Volt-Amps, Watts, kVA, kW, PF%, EFF%,
and Resistance
• Copper and Aluminum Wire Sizes
• Parallel and Derated Wire Sizes
• Voltage Drop Wire Sizes, % and Actual Voltage Drops,
Voltage Drop Distances and Wire Resistances
• Kilowatt hours and BTU’s
• Parallel Resistance
• Grounding Conductors Sizes
• Motor Full-Load Amps
• Overload Protection Sizes
• NEMA Starter Sizes
• Conduit Sizes
• And much more!

4 — electricalc®Pro
GETTING STARTED
You may want to practice getting a feel for your calculator keys by
reading through the key denitions and learning how to enter data,
how to store values, etc., before proceeding to the examples.
KEY DEFINITIONS
Basic Function Keys

On/Clear Key — Turns on power. Pressing once
clears the last entry and the display.
Pressing twice clears all temporary values.

Off — Turns all power off. Clears all non-
permanent values.


Arithmetic operation keys.
-
and 
Keys used for entering numbers.

Second Function — Used with other keys to
access secondary functions.

Store —Used for storing values.

-
Storage Registers M1 through M9 — Used to
store values in Memory registers 1 through 9.

Recall — Used with other keys to recall stored
values and settings.

Memory Clear — Clears Accumulative Memory
and displays total.

Accumulative Memory — Adds displayed value
to Accumulative Memory.

Memory Recall — Displays the value saved in
the Accumulative Memory register.

User'sGUide — 5
(cont’d)

Memory Clear (M-R/C) — Clears Accumulative
Memory without changing current display.

Percentage — Used to nd a given percent
of a number.

x2— Squares the value on the display.

Backspace Function — Used to delete entries
one keystroke at a time (unlike the  function,
which deletes the entire entry).

Square Root ( ! )— Calculates the Square
Root of the number on the display.

Reciprocal (1/x)—Finds the Reciprocal of
a number (e.g.,  0.125).

Clear All — Returns all stored values to the default
settings. Does not affect Preference Settings.

Change Sign (+/–) — Toggle displayed value
between negative and positive value.

Pi — Displays value of π (3.1415927).
Mode Set-up Keys

Preference Settings (Prefs) — Use to
dene calculator modes (see Preference
Settings section).

Single-Phase (1Ø) — Sets calculator to Single-
Phase mode.

Three-Phase (3Ø) — Sets calculator to
Three-Phase mode. This is the default setting.

6 — electricalc®Pro
(cont’d)

Ambient Temperature (Amb°) — Permanently
enters ambient temperature for determining
ampacity-derived Wire Sizes. Ambient temperature
will only change when entering a new value or by
resetting the calculator. Defaults to 30°C (86°F).
Amb will display when the Ambient Temperature is
other than 30°C (86°F).
Note: The temperature units can be displayed in
Celsius (°C) or Fahrenheit (°F) by changing the
Preference Setting (see Preference Settings section).

Copper/Aluminum (Cu/Al) — Used to toggle
between Copper (default) and Aluminum
Wire Types. When the Wire Type is revised,
any calculated Wire Size will be re-calculated
automatically. If a Wire Size is entered with the
wrong Wire Type, pressing  will change
the material type without changing the size.

Free Air (FrAir) — Sets calculator to Free Air
mode, which refers to NEC Table 310.15(B)(17)
for Wire Size calculations.

60°C Wire Insulation — Sets calculator to 60°C
Wire Insulation Type for Wire Size calculations.
This is the default setting.

75°C Wire Insulation — Sets calculator to 75°C
Wire Insulation Type for Wire Size calculations.

90°C Wire Insulation — Sets calculator to 90°C
Wire Insulation Type for Wire Size calculations.
Electrical Keys

kilo- — Used with Watts, Amps, Volts, and
Volt-Amps keys to identify “kilo-” values.

User'sGUide — 7
(cont’d)

milli- — Used with Watts, Amps, Volts, and
Volt-Amps keys to identify “milli-” values.

Amps — Enters or calculates Amps (using Volts
and VA or Watts).

Volts — Enters or calculates Volts (using
Amps, HPth, and VA or Watts). Default value
is 240 Volts.

Volt-Amps — Enters or calculates Volt-Amps
(using Amps, Volts and Horsepower or Watts).

Watts — Enters or calculates Watts (using Amps,
Volts, and VA or Horsepower).

DC Amps (Idc) — Enters or calculates DC Amps
(using DC Volts and Resistance).

DC Volts (Vdc) — Enters or calculates DC Volts
(using DC Amps and Resistance).

DC Resistance (R) — Calculates and displays
DC Resistance in Ohms (using DC Volts and
DC Amps).

Power Factor (PF%) — Enters or calculates
Power Factor percentage (based on Watts
and VA). Default value is 100%. Entered or
calculated Power Factors greater than 100%
will result in an error.

Theoretical Horsepower — Enters or calculates
Theoretical Horsepower (based on Amps, VA,
Watts, Efciency%, PF%, and/or Volts). 1.0 HPth
correlates to 746 Watts at 100% Efciency.

8 — electricalc®Pro
(cont’d)

Efficiency (Eff %) — Enters or calculates the
percent ratio between real power (Watts) and
Theoretical Horsepower. Default value is 100%.
Entered or calculated Efciencies greater than
100% will result in an error.

Kilowatt–Hours to BTU (Kw-hr ►Btu) —
Calculates BTU (British Thermal Unit) based on
an entered Kilowatt-Hour value.

BTU to Kilowatt–Hours (Btu ►Kw-hr) —
Calculates Kilowatt-Hours based on an entered
BTU (British Thermal Unit) value.

Parallel Resistance (Par Res) — Calculates
total Resistance based on an entered series of
Parallel Resistor values.
Motor Keys
The ElectriCalc Pro can be used to determine motor Full-Load Current
(Amps) based on entries for Motor Horsepower (HPmotor), Phase
and Voltage. You can also nd an equivalent Motor Horsepower if you
have entered Voltage and Full-Load Current values. Only HP Motor
and Voltage entries as dened by NEC Tables 430.247, 430.248 and
430.250 can be used to determine motor loads.

Induction/Synchronous/DC Motor Toggle
(Ind/Sync/DC) — Toggles between Induction,
Synchronous, and Direct Current Motor Types.

Motor Horsepower —Enters or calculates
Motor Horsepower.

Starter Size (Starter) — Displays the Starter
Size (from NEMA publication ICS 2-1988 Tables
2-327-1 and 2-327-2) based on the Phase,
Voltage, and Motor Horsepower settings.
Note: Horsepower values not identied in NEMA
tables will cause the calculator to round up to the
next larger Starter Size in the table.

User'sGUide — 9
Wire Sizing Keys
The ElectriCalc Pro uses NEC Table 310.15(B)(16) (310.15(B)(17)
for Free Air) to nd Wire Sizes and Ampacity ratings of wires. The
calculator uses the following data to calculate Wire Size:
1) Insulation temperature rating (60°C, 75°C and 90°C)
2) Wire material (Copper or Aluminum)
3) Ambient Temperature
Standard AWG Wire Sizes and Circular Mils are used by the
ElectriCalc Pro. Wire Size entries less than or equal to 2,000 are
accepted as AWG Wire Sizes; entries greater than 2,000 are
accepted as Circular Mil entries and display the corresponding AWG
Wire Size. Entries must match the standard Wire Sizes or Circular
Mils; otherwise, nonE will be displayed (invalid entry).
Note: 1/0, 2/0, 3/0 and 4/0 wires are entered using the key
(e.g., 0, 00, 000 and 0000).

Wire Size/Ampacity — Enters or calculates Wire
Size based on Ampacity and Voltage Drop, if a
Voltage Drop Length has been entered.
♦ First Press
If a Wire Length has been entered, the rst
press will show the larger of the Ampacity or
Voltage Drop derived Wire Size. The calculator
will use the larger value when calculations
require a Wire Size. If no Voltage Drop Length
has been entered, the calculator will display the
calculated Ampacity-rated Wire Size.
♦ Second Press
If a Wire Length has been entered, the second
press displays the smaller of the two Wire
Sizes. If not solving for Voltage Drop Wire Size,
then displays the maximum Ampacity.
♦ Third Press
Displays the Wire Size in Circular Mils.
(cont’d)

10 — electricalc®Pro
(cont’d)
♦ Fourth Press
If a Wire Length has been entered, displays
the minimum Wire Ampacity rating. If no Wire
Length has been entered, displays the NEC
table referenced for the calculation.

125% Ampacity — Used for Motor Wire Sizing
when the Wire must not exceed 80% of its rated
Ampacity (125%A). This keystroke calculates Wire
Size based on 125% of the entered or calculated
Amps value.

Parallel Size — Used to nd the size of parallel
conductors using Amperage and an entered
quantity of Wires. Parallel Wire Size calculations
smaller than 1/0 will display nonE, as the NEC
does not allow Parallel Wire runs smaller than 1/0.
♦ First Press
When preceded by a number, calculates the
applicable Wire Size for that quantity of
Wires in parallel.
♦ Second Press
Displays the maximum adjusted Ampacity of the
calculated Parallel Wire Size.
Note: No adjustments are made for deration.

Derated Wire Size (D/R Size) — Used to
calculate Derated Wire Sizes and allowable
Ampacity based on the entered quantity of wires,
NEC Table 310.15(B)(16) and NEC Table
310.15(B)(3)(a). Derated Wire Sizes are not
calculated when there are less than four Wires, or
when the unit is in Free Air mode.
♦ First Press
Calculates the Derated Wire Size, if you have
entered the number of Wires.

User'sGUide — 11
(cont’d)
♦ Second Press
Displays the maximum adjusted Ampacity
of the Derated Wire Size.
♦Third Press
Displays the Derated Adjustment Factor per
the NEC Table 310.15(B)(3)(a).
♦ Fourth Press
Displays the NEC table referenced
for the calculation.
Voltage Drop Keys
The ElectriCalc Pro will calculate maximum Lengths, minimum Wire
Sizes or actual Voltage Drops given the other two values. Voltage
Drop solutions are based on the DC Resistance values found in
NEC Chapter 9, Table 8.
Note: Voltage Drop solutions may vary slightly from actual AC circuit
values as the calculator does not incorporate factors such as inductive
reactance, skin effect, raceway material, etc.

Percent Voltage Drop — Used to enter or
calculate Voltage Drop. The default Voltage Drop
is 3%. If Wire Size or Wire Length values are not
available, nonE will display, since the Voltage
Drop cannot be found.
♦ First Press
Enters a maximum allowable Voltage Drop
percentage or calculates actual Voltage Drop.
♦ Second Press
Calculates actual percent Voltage Drop.

Length — Enters or calculates the Length of a
run for Voltage Drop calculation.
Note: Units of Length can be set to Feet or
Meters by changing the Preference Setting (see
Preference Settings section).

12 — electricalc®Pro
(cont’d)

Wire Resistance (Wire Res) — Displays the
actual Resistance per 1,000 Feet of the Wire Size
in  based on NEC Chapter 9, Table 8.
Grounding Conductor Keys

Ground — Used to nd the Grounding electrode
conductor size for AC systems based on NEC
Table 250.66 and an entered or calculated
service-entrance conductor (largest size). Only
actual Wire Sizes are considered valid entries.
♦ First Press
Calculates the copper Grounding electrode
conductor size if you have entered a valid
Wire Size.
♦ Second Press
Displays the aluminum Grounding electrode
conductor size.
♦ Third Press
Displays the Circular Mil area used to calculate
the Grounding electrode conductor size.
♦ Fourth Press
Displays the NEC table referenced for
the calculation.

Equipment Ground (EqGrnd) — This function
uses NEC Table 250.122 to calculate the
minimum equipment Grounding conductor size,
given an entered Amperage rating or setting for
an over-current device up line.
Note: This function deviates from the NEC Table
250.122 in that 1250 MCM AL is used instead of
1200 as specied in NEC Table 250.122.
♦ First Press
Displays the copper Grounding conductor size
for the entered Amp rating.

User'sGUide — 13
(cont’d)
♦ Second Press
Displays the aluminum Grounding
conductor size.
♦ Third Press
Displays the NEC table referenced for
the calculation.
Fuse/Breaker Keys
The ElectriCalc Pro has special keys that automatically calculate the
Amp ratings of the following over-current protection devices: Dual
Element Fuses (Time Delay), Single Element Fuses (Non-Time
Delay), Instantaneous Trip Breakers (Type 1), Inverse Time Breakers
(Type 2), and Overload Protection Devices.
These Fuse and Circuit Breaker sizes are derived using the “Percent
of Full-Load Current” multipliers listed in NEC Table 430.52.
If a parameter is missing or invalid, the calculator will display nonE.

Overload Protection —
♦ First Press
Displays the Overload Amperage requirement
based on the Full-Load Current shown on the
motor nameplate. Multiplies the entered
motor nameplate Full-Load Current
(stored in the
 register) by 115% or
the value you enter.
Conforms to NEC Section 430.32(A)(1) value
of 115%, unless you enter another value. For
example, entering 125  would calculate
Overload protection based on 125% of the
entered Amperage.

14 — electricalc®Pro
♦ Second Press
Displays the Full-Load Current percent
multiplier value used to determine the Overload
current protection size. Subsequent presses of
 repeat the cycle.

Motor Type (M-Type) — Based on NEC Table
430.52, this function selects the Motor Type used
to dene the percent factors for Breakers/Fuses.
Once set, the Motor Type remains xed
until you change it or perform a Clear All
(  ).
♦ First Press
Displays the current Motor Type. Note there is
no Motor Type in Single-Phase mode.
♦ Second Press
In Three-Phase mode only, subsequent
presses of
 will select and display the
next Motor Type from this list: SQ-C non-b
(Squirrel Cage, non-Design B), SQ-C b
(Squirrel Cage, Design B), SYNC no codE
(Synchronous), WND no codE (Wound Rotor).
Dual Element Fuse
—
♦ First Press
Calculates the minimum Amp rating for a
Dual Element Fuse.
♦ Second Press
Displays the Full-Load Current percent
multiplier used to determine Fuse size.

Single Element Fuse (SEFuse) —
♦ First Press
Displays the minimum Amp rating based on
Phase, Motor Type, and Amperage.
(cont’d)

User'sGUide — 15
(cont’d)
♦ Second Press
Displays the Full-Load Current percent
multiplier value used to determine Fuse size.
Subsequent presses repeat this cycle.

Inverse Time Breaker —
♦ First Press
Displays the minimum Amp rating for an
Inverse Time Breaker, based on the Phase,
Motor Type, and Amperage.
♦ Second Press
Displays the Full-Load Current percent multiplier
value used to determine Breaker Size.

Instantaneous Trip Circuit Breaker (InsTrip) —
♦ First Press
Displays the minimum Amp rating for an
Instantaneous Trip Circuit Breaker, based on
the Phase, Motor Type, and Amperage.
♦ Second Press
Displays the Full-Load Current percent multiplier
value used to determine Breaker Size.
Conduit Sizing Keys
The ElectriCalc Pro calculates Conduit Size using NEC Tables 1, 4
and 5 of Chapter 9 (given Insulation Type, Wire Size, and quantity
of Wires). It will also calculate the Number of Wires of a specied
Insulation Type and Wire Size that will t in a dened Conduit Size.
Acceptable Conduit Sizes (depending on the type of Conduit used)
are as follows: 1/2", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3", 3-1/2", 4",
5", and 6". Conduit Sizes are entered using decimal equivalents (e.g.,
1-1/2"is entered as 1.5, 3/4"is entered as 0.75, etc.).

16 — electricalc®Pro
,,

Number of Wires — Used to enter or calculate
the Number of Wires in a raceway and calculate
cross-sectional Wire Area.
♦ First Press
Enters Number of Wires or calculates
maximum Number of Wires in Conduit.
♦ Second Press
Shows total cross-sectional area for all
entered Wires.
♦ Third Press
Shows total cross-sectional area of all entered
Wires of the selected Wire Insulation.

Conduit Size — Used to nd Conduit Sizes
based on the total area of the entered Wire
Types and Wire Sizes (up to 15 at one time). If
the quantity and Insulation Type have not been
entered, the calculator will assume 2 THHN Wires
for Single-Phase or 3 THHN Wires for Three-
Phase calculations.
♦ First Press
Enters or calculates Conduit Size.
Note: If a Wire Size has not been entered or
calculated, or an invalid Conduit Size is entered, the
calculator will display nonE.
♦ Second Press
Shows Total Number of Wires in the Conduit
for calculated Conduit Size. Shows the Conduit
internal Area for an entered Conduit.
Note: Third through fth presses will only be
displayed for calculated Conduit Sizes.
(cont’d)

User'sGUide — 17
♦ Third Press
Shows Fill Percentage for the calculated
Conduit Size as determined by NEC
Table 1, Chapter 9.
♦ Fourth Press
Shows the Total Wire Area for all entered Wires.
♦ Fifth Press
Shows Remaining Fill Area. This value may be
negative if all Wires are the same size due to
Note 7 in NEC Chapter 9, Table 1.

Conduit Type (Cond Type) — Used to select
the desired Conduit Type. Pressing these keys
with a value between 1 and 12 will select the
corresponding Conduit Type, as specied in the
list below (i.e., selects the EMT
Conduit). Continuous presses of toggle
through the available Conduit Types.
♦ First Press
Displays the currently selected Conduit Type.
1) EMT
2) ENT
3) FMC
4) IMC
5) LFNB
6) LFNA
7) LFMC
8) RMC
9) P-80
10) P-40
11) P-A
12) P-EB

18 — electricalc®Pro
PREFERENCE SETTINGS
Press , then to access the Preferences menu. Continue
pressing to toggle through different Preferences. Press  or 
keys to toggle between options of the different Preferences. Press
 to exit Preferences. Your calculator will keep your Preference
Settings until a Full Reset alters your settings to the default values
(see Appendix for more information).
KEYSTROKE DISPLAY
(Prefs)
(NEC Code) 2011
 1996
 1999
 2002
 2005
 2008
 (repeats options) 2011
Second press of :
(Ambient Temperature Units) AMBº 30. ºC*
 AMBº 86. ºC*
(repeats options) AMBº 30. ºC*
* These values will differ if you have changed the Ambient Temperature.
Third press of :
(Length Units) FEET 1.
 MET 1.
(repeats options) FEET 1.

User'sGUide — 19
(cont’d)
baSIC maTh OPERaTIONS
This calculator uses standard chaining logic, which simply means
that the entered mathematical string is evaluated from left to right
without any priority given to different operators.
KEYSTROKE DISPLAY
 5.
 1.
 6.
 1.5
PERCENT CalCulaTIONS
The  key can be used for nding a given percentage of a number
or for working add-on, discount or division percentage calculations.
KEYSTROKE DISPLAY
 53.25
 266.25
 23.75
 200.
The key also allows you to change percentages to decimals
(e.g., displays 0.25).
mEmORY OPERaTIONS
Whenever the keys are pressed, the displayed value will be
added to the Cumulative Memory. Other Memory functions:
FUNCTION KEYSTROKE
Add to Memory 
Subtract from Memory 
Recall total in Memory  
Display/Clear Memory 
Clear Memory 