Calculated Industries ElectriCalc LT User manual

ElectriCalc
®
LT
An Electrician's Utility for Wiring
User's Guide

IMPORTANT NOTE ON
USER RESPONSIBILITY
Due to the serious nature of electrical
installations, the user of this calculator
must be certain that he or she is using it
correctly, i.e., in accordance with both
the following instructions and National
Electrical Code®requirements.
This tool was designed to work with the
1999 NEC®, not replace it. Users, espe-
cially those unfamiliar with the Code,
should exercise appropriate caution.
If questions arise as to the correctness
of an answer given by the calculator, or
if an answer appears to conflict with the
Code, the user should always defer to
the Code.
If used responsibly and correctly, this
tool will save the user hours of tedious
calculation and look-up time, reduce
material costs, and provide safe, accu-
rate, Code-legal answers.
National Electrical Code and NEC are
registered trademarks of the National
Fire Protection Association, Inc.,
Quincy, MA 02269

User's Guide — 1
Introducing the
ElectriCalc®LT
The
ElectriCalc
®
LT
is an invaluable
calculator for today’s busy electrical
professional. Unlike a regular calculator,
it has intuitively labeled “electrical keys”
and conforms to the 1999
National
Electrical Code,
allowing you to solve
Code-related problems quickly and
accurately. Common NEC tables are
built in, providing instant solutions for
the following:
♦Volts, Amps, Volt-Amps, Watts,
kVA, kW, PF%, EFF%, and DC
Resistance
♦Copper or Aluminum Wire Sizes
♦Parallel & Derated Wire Sizes
♦Voltage Drop Wire Sizes, % and
Actual Voltage Drops, Voltage
Drop Distances and Wire Resis-
tances
♦Grounding Conductors Sizes
♦And much more!

2 — ElectriCalc LT
Table of Contents
Key Definitions
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3
Default Settings
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16
Basic Math Operations
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17
Percent Calculations
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17
Memory Functions
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18
Kerchoff’s Law
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19
Ampacity Wire Sizing
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24
Voltage Drop
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31
Error Codes
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39
1999 NEC References
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39
Battery Information
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40
Settings
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40
Warranty
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41
Legal Notices
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45

User's Guide — 3
Key Definitions
Standard Calculator Functions
[On/C] — On/Clear
Turns on power. Pressing once clears
the last entry and the display. Pressing
twice clears all non-permanent values.
[Off] — Off
Turns all power off. Clears the memory
and most internal registers.
[Set] — Second Function
Accesses the secondary functions
shown above the keys when pressed
prior to selection.
[Rcl] — Recall
Recalls a value stored in a register
(e.g., to recall voltage drop % press
[Rcl] [VD%]).
[Rcl] [Rcl] — Display/Clear Memory
Displays and clears the value saved in
(M+).
[Set] [Rcl] — Clear Memory
Clears the value saved in [M+] without
changing displayed value.

4 — ElectriCalc LT
[M+] — Cumulative Memory
Adds displayed value to Memory (e.g.,
10 [M+], 20 [M+], [Rcl] [M+] = 30).
Clears when the calculator is shut off.
[Set] [M+] — Memory Minus (M−)
Subtracts the displayed value from
Memory.
[+] [–] [x] [÷] [=]
Arithmetic operation keys.
[Set] [–] — Change Sign (+/–)
Toggles the sign of the displayed value
(from positive to negative or from nega-
tive to positive).
[Set] [÷] — Reciprocal (1/x)
Reciprocal, or 1/x function.
[0] – [9] & [ • ]
Digits used for keying in numbers.
[Set] [ . ] — x2
Squares the displayed value.
[%] — Percent
Four function percent key.
[Set] [%] — Square Root ( x )
Square root function.

User's Guide — 5
Mode "Set-Up" Functions
[Set] [x] — All-Clear (AC)
Resets all settings and values to their
default settings.
[CU/AL] — Copper/Aluminum
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 [CU/AL] will change
the material type without changing the
size.
Displays: Al or Cu
[Set] [1] — Single-Phase (1Ø)
Sets calculator to single-phase mode.
Displays: 1Ø.
[Set] [3] — Three-Phase (3Ø)
Sets calculator to three-phase mode.
Displays: 3Ø.
[Set] [6] — 60°C Wire Insulation
Sets calculator to 60°C wire insulation
type for wire size calculations. This is
the default setting. Displays: 60.
[Set] [7] — 75°C Wire Insulation
Sets calculator to 75°C insulation type
for wire size calculations. Displays: 75.

6 — ElectriCalc LT
[Set] [9] — 90°C Wire Insulation
Sets calculator to 90°C insulation type
for wire size calculations. Displays: 90.
[Set] [2] — Ambient Temperature
Permanently enters ambient tempera-
ture for determining ampacity derived
wire sizes. Ambient temperature will
only change when entering a new value
or by resetting the calculator ([Set] [x]).
Defaults to 30°C (86°F). Amb° will dis-
play when the ambient temperature is
other than 30°C (86°F).
Displays: Amb°.
[Set] [4] — Feet/Meters Toggle
Toggles between feet and meters.
Displays: FEET or MET.
[Set] [5] — Free Air (FrAir)
Sets calculator into Free Air mode,
which refers to NEC Table 310-17 for
wire size calculations. Revises back to
Raceway mode when calculator is pow-
ered down. Displays: FrAir.
[Set] [+] — °C/°F Toggle
Toggles ambient temperature format
between °C and °F. Converts displayed
temperature value automatically.
Displays: °C or °F.

User's Guide — 7
Electrical Functions
[kilo-] — Kilo-
This key is used with watts, amps, volts,
and volt-amps to identify "kilo-" values.
[Set] [kilo-] — Milli-
This key is used with other keys watts,
amps, volts, and volt-amps to identify
"milli-" values.
[Amps] — Amps
Enters or calculates amps (using volts
and VA or watts). Displays: AMPS,
KAMP.
[Volts] — Volts
Enters or calculates volts (using amps,
HPth, and VA or watts). Default value is
240 volts. Displays: VOLT, KV, or mV.
[Set] [Volts] — DC Resistance
Calculates and displays DC resistance.
Displays: OHMS.
[VA] — Volt-Amps
Enters or calculates volt-amps (using
amps, volts and horsepower or watts).
Displays: VA, KVA, or mVA.

8 — ElectriCalc LT
[Watts] — Watts
Enters or calculates watts (using amps,
volts, and VA or horsepower).
Displays: WATT, KW, or mW.
[Set] [Watts] —Power Factor
Enters or calculates power factor per-
centage (based on watts and VA). De-
faults to 100%. Entered or calculated
power factors greater than 100% will
result in an error. Displays: PF%.
[HPth] — Horsepower (Theoretical)
Enters or calculates theoretical horse-
power (based on Amps, VA, watts, effi-
ciency%, PF%, and/or volts). 1.0 HPth
correlates to 746 watts at 100% effi-
ciency. Displays: HPth.
NOTE: This horsepower should not be
confused with the motor horsepower
keys used to determine motor load.
[Set] [HPth] — Efficiency
Enters or calculates the percent ratio
between real power (watts) and theo-
retical horsepower. Default: 100%. En-
tered or calculated efficiencies greater
than 100% will result in an error. Dis-
plays: EFF%.