Exam Cheat Sheet · Quick Reference

Texas - Master Sign Electrician

Texas  ·  PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
100
Passing score
70%
Exam time
300 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

Texas State Portion 100 questions

Definitions, Calculations, and Theory 6 Q · 6%
Electrical Services, Service Equipment, and Separately Derived Systems 16 Q · 16%
Electrical Feeders 3 Q · 3%
Branch Circuit Calculations and Conductors 15 Q · 15%
Electrical Wiring Methods and Electrical Materials 8 Q · 8%
Electrical Equipment and Devices 10 Q · 10%
Motors 2 Q · 2%
Electrical Control Devices and Disconnecting Means 4 Q · 4%
Electric Signs and Outline Lighting 36 Q · 36%

Key Distinctions

Neon tubing branch circuitvsAll other signs/outline lighting branch circuit

Neon tubing installations may be supplied by a branch circuit rated up to 30 amperes, while all other signs and outline lighting systems are limited to 20 amperes.

NEC 600.5(C)(1)
Maximum secondary-circuit voltage (15,000 V)vsMaximum voltage to ground (7,500 V)

The total secondary-circuit voltage must not exceed 15,000 volts nominal under any load, but the voltage to ground of any single output terminal must not exceed 7,500 volts.

NEC 600.23(C)
Secondary conductor max length in metal conduit (20 ft)vsSecondary conductor max length in nonmetallic conduit (50 ft)

From a high-voltage terminal to the first neon tube electrode, metal conduit limits the run to 6 m (20 ft), whereas nonmetallic conduit allows up to 15 m (50 ft).

NEC 600.32(J)(1)
Required commercial sign outlet (20 A)vsMaximum branch circuit for neon (30 A)

NEC 600.5(A) mandates at least one 20-ampere dedicated outlet at each commercial occupancy for sign use, while 600.5(C)(1) separately allows neon tubing circuits to be rated up to 30 amperes.

NEC 600.5(A)
Neon tubing spacing from nearest surface (1/4 in.)vsNonmetallic conduit spacing from grounded parts (1-1/2 in.)

Neon tubing itself must be kept at least 6 mm (1/4 in.) from any adjacent surface other than its support, while nonmetallic conduit carrying a conductor at 100 Hz or less must be at least 38 mm (1-1/2 in.) from grounded or bonded parts.

NEC 600.41(C)
Listed/labeled requirement — fixed signsvsListed/labeled requirement — mobile/portable signs

NEC 600.3 requires all electric signs to be listed and labeled regardless of whether they are fixed, mobile, or portable, and regardless of voltage.

NEC 600.3
Minimum conduit size for neon secondary circuit (trade size 1/2)vsMinimum conductor size for neon secondary circuit (18 AWG)

Conduit or tubing for neon secondary circuits over 1000 V must be at least metric designator 16 (trade size 1/2), while the conductors inside must be type GTO and not smaller than 18 AWG.

NEC 600.32(A)(3)
Sign height above vehicle areas (14 ft)vsWorking space at transformers/power supplies (3 ft × 3 ft × 3 ft)

Equipment above vehicle-accessible areas must be at least 4.3 m (14 ft) high per NEC 600.9(A), whereas a separate 900 mm × 900 mm × 900 mm (3 ft cube) working space is required at each transformer or power supply not mounted inside a sign per NEC 600.21(D).

NEC 600.9(A)
Flexible metal conduit as bonding means (max 100 ft total)vsStandard equipment bonding

Listed flexible metal conduit or liquidtight flexible metal conduit enclosing neon secondary conductors may serve as the bonding means only if the total accumulative length in the secondary circuit does not exceed 30 m (100 ft); beyond that length a separate bonding conductor is required.

NEC 600.7(B)(4)

Key Terms

Listed and Labeled Requirement (NEC 600.3) NEC 600.3
Per NEC 600.3, all fixed, mobile, or portable electric signs, section signs, outline lighting, PV-powered signs, and retrofit kits, regardless of voltage, must be listed and labeled and installed in conformance with that listing.
Commercial Sign Outlet Requirement (NEC 600.5(A)) NEC 600.5(A)
Per NEC 600.5(A), each commercial building or occupancy accessible to pedestrians must have at least one dedicated outlet rated at least 20 amperes for sign or outline lighting use.
Neon Branch Circuit Rating (NEC 600.5(C)(1)) NEC 600.5(C)(1)
Per NEC 600.5(C)(1), branch circuits supplying neon tubing installations shall not be rated in excess of 30 amperes.
Non-Neon Sign Branch Circuit Rating (NEC 600.5(C)(2)) NEC 600.5(C)(2)
Per NEC 600.5(C)(2), branch circuits supplying all signs and outline lighting systems other than neon tubing shall be rated not to exceed 20 amperes.
Vehicle Clearance Height (NEC 600.9(A)) NEC 600.9(A)
Per NEC 600.9(A), sign or outline lighting system equipment must be installed at least 4.3 m (14 ft) above areas accessible to vehicles unless protected from physical damage.
Maximum Secondary-Circuit Voltage (NEC 600.23(C)) NEC 600.23(C)
Per NEC 600.23(C), the secondary-circuit voltage of transformers and electronic power supplies shall not exceed 15,000 volts nominal under any load condition, and voltage to ground of any output terminal shall not exceed 7,500 volts.
Maximum Secondary-Circuit Current (NEC 600.23(D)) NEC 600.23(D)
Per NEC 600.23(D), transformers and electronic power supplies used with electric signs shall have a secondary-circuit current rating of not more than 300 mA.
Neon Secondary Conductor Length — Metal Conduit (NEC 600.32(J)(1)) NEC 600.32(J)(1)
Per NEC 600.32(J)(1), secondary circuit conductors from a high-voltage terminal to the first neon tube electrode must not exceed 6 m (20 ft) when installed in metal conduit, or 15 m (50 ft) in nonmetallic conduit.
Neon Tubing Surface Spacing (NEC 600.41(C)) NEC 600.41(C)
Per NEC 600.41(C), neon tubing must maintain a minimum spacing of 6 mm (1/4 in.) from the nearest adjacent surface other than its support.
Nonmetallic Conduit Spacing from Grounded Parts (NEC 600.32(A)(4)) NEC 600.32(A)(4)
Per NEC 600.32(A)(4), nonmetallic conduit containing a neon secondary conductor operating at 100 Hz or less must be spaced at least 38 mm (1-1/2 in.) from any grounded or bonded part.
Minimum Conduit Size — Neon Secondary Circuit (NEC 600.32(A)(3)) NEC 600.32(A)(3)
Per NEC 600.32(A)(3), conduit or tubing used for neon secondary circuits over 1000 V shall be a minimum of metric designator 16 (trade size 1/2).
GTO Cable / Minimum Conductor Size (NEC 600.32(B)) NEC 600.32(B)
Per NEC 600.32(B), conductors for neon secondary circuits over 1000 V must be listed gas tube sign and ignition cable type GTO and shall not be smaller than 18 AWG.
Flexible Metal Conduit as Bonding Means (NEC 600.7(B)(4)) NEC 600.7(B)(4)
Per NEC 600.7(B)(4), listed flexible metal conduit or liquidtight flexible metal conduit enclosing neon secondary conductors may serve as the bonding means provided the total accumulative length does not exceed 30 m (100 ft).
Working Space at Transformers/Power Supplies (NEC 600.21(D)) NEC 600.21(D)
Per NEC 600.21(D), a working space at least 900 mm × 900 mm × 900 mm (3 ft × 3 ft × 3 ft) must be provided at each ballast, transformer, electronic power supply, or Class 2 power source not installed inside a sign.
Sheet Steel Minimum Thickness (NEC 600.8(C)) NEC 600.8(C)
Per NEC 600.8(C), sheet steel used in sign and outline lighting system enclosures must be at least 0.41 mm (0.016 in.) thick.
Maximum Lamp Wattage Marking (NEC 600.4(C)) NEC 600.4(C)
Per NEC 600.4(C), electric signs with incandescent lamp holders must be marked with the maximum allowable lamp wattage in letters at least 6 mm (1/4 in.) high.
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