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AC Voltage Calculator
Convert between peak, peak-to-peak, rms, and average AC voltage quantities.
Ansi Device Numbers
Quick search ANSI standard device numbers and their definition.
Bolt Torque Values
Look up the recommended torque value for various types and grades of U.S. standard fasteners.
Breaker MVA Calculator
Find MVA rating of a circuit breaker using nameplate ratings.
Contact Resistance DB
Compare contact-resistance to real world values submitted by TestGuy members.
Digitrip GF Pickups
Find expected Ground Fault pickup values for most Digitrip RMS trip units.
Electrical Symbols
Browse common electrical diagram symbols or search dynamically by name.
Fall of Potential
Electronic form for saving fall of potential test data.
Insulation Resistance Values
Correct insulation resistance (IR) test results to 20°C or 40°C and lookup recommended values.
Loss of Excitation
Calculate useful values for testing GE & SEL generator protection relays.
Maintenance Frequency
Get recommended maintenance service intervals for power distribution equipment.
Motor Calculations
Find FLA and torque for electric motors or convert between Horsepower and Watts.
My Progress
Review past exam scores and get stats on your progression.
Ohm's Law Calculator
Calculate the relationship between voltage, current, and resistance or the relationship between power, voltage, and current.
Percent Error Calculator
Calculate percent error with calibrated and actual results.
Power Factor Calulations
Calculate power factor for single- and three-phase circuits and find correction capacitor.
Power Triangle Calculator
Find PF, VAR, W and VA with any two known quantities or review power triangle formulas.
TOC/IDMT Calculator
Calculate the protection trip time (TOC/IDMT) according to IEC 60255 and IEEE C37.112-1996 protection curves.
Tech Quiz
Distraction free testing environment.
Terms and Definitions
A complete library of terms related to electrical testing, with dynamic search.
Test Unit Converter
Convert between common test values such as Mega to Kilo and Base to Micro.
Transformer Calculations
Get recommended test values, find TTR and load currents for single- and three-phase transformers.
Trip Unit TCC Calculator
Generate test currents and generic trip times for LSIG trip units, includes tolerance for pickup and time values.
Voltage Drop Calculator
Estimate the voltage drop of an electric circuit based on the wire size, distance, and anticipated load current.
Wire Size Calculator
Calculate the appropriate low-voltage wire size based on NEC Article 310.15.

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