Practical selection criteria and quick calculations
Two quick checks you should do before ordering: verify conductor cross-section compatibility and confirm the continuous current the fitting will carry. Use Ohm’s law and power basics for strain and heating checks when unsure.
Useful formulae
Ohm’s law: V = I × R. Power dissipation: P = I^2 × R. For thermal selection, check the terminal or lug datasheet for continuous current and derating tables.
Wiring diagram example (single-phase distribution)
Mains L -----[MCB]-----[Terminal block]-----(to load)
Mains N -------------------------------------(to load)
Earth -------------------------------------(to earth lug)
This ASCII sketch shows how terminal blocks and lugs sit between protection (MCB) and the load. When ordering, choose terminal blocks rated above your MCB continuous current with matching conductor size.
Troubleshooting and procurement notes for South Africa
Common issues are wrong gland thread, undersized lugs, and missing mounting hardware. To prevent delays, check stock in branch and lead time information. Use our Branches & Trading Hours page to plan pickup and collection: Branches & trading hours.
Availability and lead times
We maintain stock in Samrand and selected branches for high-turn items. For larger or branded orders, expect lead times to vary - request a formal quote to lock pricing and delivery on our account system. For a broad search across stock, see our complete product index: All products.
Brands and education use
We stock a wide brand mix spanning maker-friendly and industrial lines. For classroom and lab purchasing, Communica supports VAT invoicing, quotes for institutions and educational discounts where applicable - check our About page for company credentials and purchasing policies: Communica information.
Objection handling and final summary
Concerned about matching specs or missing parts? Our product pages list compatible accessories and typical applications; for tailored help, request a quote and our team will confirm fitment and shipping. Want to inspect before you buy? Check stock in Samrand or at a nearby branch for same-day pickup.
Communica combines deep stock levels with practical procurement features: branch pickup, VAT invoicing, accessory bundles, and compatibility guidance - all focused on South African makers, students and procurement teams. If you need a recommended list for a project or a formal supply quote, use the options below to Shop Now, Check Stock in Samrand, Compare Specs or Request a Quote and we’ll help assemble the right fittings and extras.
