Electrical — FAQ
What joules rating do electricians actually need?
For job sites, minimum 1500 joules. Motor startups and utility switching create repeated surges. Higher ratings extend lifespan. Whole-house units should be rated in amps—140k+ for lightning protection.
Can I daisy-chain surge protectors on job sites?
Never. NEC prohibits daisy-chaining extension devices. It creates fire hazards and voids UL listing. Use a single, properly rated strip with adequate joules and 12 AWG cord for distribution.
How often should I replace surge protectors?
After any major surge event (lightning strike, transformer failure) or every 3-5 years under normal use. Most units have indicator lights—replace immediately when protection light extinguishes.
What's the difference between Type 1 and Type 2 SPDs?
Type 1 installs before the main breaker (line side). Type 2 installs after (load side). Type 1 requires utility notification. Both protect the panel, but Type 1 handles external surges better.
Do magnetic mounts interfere with sensitive equipment?
No. Static magnetic fields from mounting bases don't affect multimeters, testers, or electronics. The field strength is too low and too localized. Klein Tools unit tested safe with Fluke meters.
Are whole-house surge protectors worth it for clients?
Absolutely. At $100-200 installed, they protect $10k+ of appliances and electronics. Many insurers offer discounts. NEC 2020 requires them in new construction—recommend retrofitting older homes.
