Help needed with Central Vac outlet wiring - DoItYourself Jun 24, 2010Help needed with Central Vac outlet wiring. Our central vac was been roughed in by pros, but now I have to connect the outlets but don't understand how to wire them. Each outlet has two posts, and there are also two sets of two white wires (one is silver and one is copper colored when the insulation is removed). Help With Wiring Central Vac Inlets - Electrical - DIY May 23, 2011Help with wiring Central Vac Inlets. I purchased a Beam central vac and the manual really gets into no detail whatsoever. Yea, that's the original type. Installers used to install the central vac outlet near a 120v wall outlet and the hose had a separate cord that would plug into it.