Planning a multi-unit workplace installation is a sequence: fix the port count from dwell and duty evidence, confirm site electrical capacity in writing, phase the build so infrastructure goes in once, and close the access and billing questions before hardware is ordered. Choosing units before capacity is confirmed is where these projects pick up their redesigns and their second round of groundworks.
Key Takeaways
- Plan in order: count, confirmed capacity, phased build, access and billing closed before ordering.
- Size against combined nameplate ceilings, each circuit at 125% of charger current (NEC continuous-load rule).
- Phase one builds infrastructure for the whole plan; session records size phase two.
- No EVDANCE listing states site-wide load management — a written confirmation, never a design assumption.
Step One: A Count the Site Can Defend
The count comes from site evidence, not a ratio: how many EVs park there daily, how long each stays, and how much energy each needs before it leaves.
Long dwell changes the answer: a car parked all shift can share a port with a second car, so the count is usually well below one port per EV. The employer’s policy side is in our workplace charging program guide. The installer’s job here is narrower: get the count, dwell pattern and any must-be-full vehicles (pool cars, shift vehicles) in writing from the client — every later step is sized against them.
Step Two: Confirm Capacity Before Promising Ports
Workplace charging is Level 2 work: U.S. DOT figures put Level 2 at 7–19 kW per port, and ports are planned against nameplate ceilings. EV charging is a continuous load under the NEC, so each circuit is sized at 125% of the charger’s current:
| Charger current | Breaker size (NEC 125% continuous-load rule) | Planning note |
|---|---|---|
| 32 A | 40 A | The common single wallbox circuit |
| 40 A | 50 A | Check panel headroom per unit |
| 48 A | 60 A | Adds up fast across bays |
Multiply the per-unit ceiling by the count and compare it with the capacity the site’s licensed electrician confirms in writing (the utility, where the service itself would change). If confirmed capacity cannot carry the ceiling, the options are fewer ports in phase one, a supply upgrade quoted as its own line, or phasing. Never assume a product feature will stretch the supply: no EVDANCE listing states site-wide load management, so that capability is a written confirmation to request, not a design assumption.
Step Three: Phase the Build, Infrastructure First
| Phase | What goes in | Why then |
|---|---|---|
| Phase 1 — infrastructure | Supply work, cable routes and containment to every planned bay, first ports live | Routes are cheapest while the ground is open; later ports become a fitting job, not a building job |
| Phase 1 — records | Session data from the first ports: occupancy by hour, energy per session | The evidence that sizes phase 2, replacing opinion |
| Phase 2 — remaining ports | Remaining units on the prepared routes, count adjusted to recorded demand | The client funds the ports the data supports |
Step Four: Close Access and Billing Before Ordering
Multi-unit sites live or die on questions that are not electrical: who may charge, how sessions are attributed to drivers, and whether the employer bills for energy or gives charging away.
Those answers decide the hardware class — open, card-controlled or platform-recorded ports — so they are closed with the client, and confirmed with the supplier in writing, before the order.
Hardware for Multi-Bay Sites
For shared or turning-over bays, the EVDANCE EV-AC03201T dual-connector AC station serves two bays from one floor-standing unit — two Type 2 connectors sharing up to 43 kW (22 kW per connector), with OCPP 1.6J and RFID. Its stated dynamic allocation works between its own two connectors; it is not a site-wide balancing feature. For dedicated staff bays, the EV-ACT3204PE 22 kW wallbox (three-phase Type 2, RFID and app, IP66) puts one controlled point on each bay. Source through the distributor program or contact us.
Frequently Asked Questions
Should all planned ports be installed at once?
Rarely. Put the full plan’s infrastructure in during phase one — supply, routes, bay preparation — and fit ports against recorded demand. Ports are quick to add on prepared routes; groundworks are not quick to repeat.
Who confirms the site has enough capacity?
The site’s licensed electrician, from the planned units’ combined ceiling and the site’s existing load. Where the utility service itself would change, the utility’s written position is part of the confirmation — get both before the port count is promised.
Does one dual-connector station count as one charger or two?
Count connectors and bays: one dual-connector station serves two bays and two cars at once, sharing its stated total between them. Port counts are what the capacity check and the budget need.
Related Reading
- How to Plan a Workplace EV Charging Program
- Fleet Depot Charging: How to Size AC Chargers for Vans and Light Commercial Vehicles
- How Much Does It Cost to Install a Commercial EV Charging Station?
- How Do Commercial EV Charging Stations Work?
