Upgrading an older Energy Sentry system

What replaces what

Commercial and industrial sites move to the 9388B, 9388C, or 9388M depending on service type and connected load. Call us with your service size and we will tell you which one. See the model library for specifications.

What changes for the owner

Current firmware and current rate schedules. This is why most upgrades happen. The 9388A's rate selector configures the on-peak windows, season definitions, holiday calendar, and averaging period for your specific utility plan, then locks them. If your utility has revised its demand schedule since your old unit was commissioned, and most have, the old controller may be shedding at the wrong hours or not shedding when it matters.

A display you can read. Six readings on one rotary knob: instantaneous demand, average demand, peak demand, demand limit, load status, and clock.

Warranty resets to three years.

More control points. The 9388A manages 8 or 16, and most older residential units controlled fewer. Loads have changed too. A home that had a water heater and a dryer in 1995 now has an EV charger, a pool pump, and a second air conditioner. Getting those under control is where the additional savings are.

Better hardware fit. The 9388A has two low-voltage relay outputs on the board in addition to the power relays on the plate. Some older units, including certain ZDC controllers, had no low-voltage outputs, which forced installers to switch heat pumps with a power relay when a 24V control-loop connection would have been correct and cheaper.

Roughly three months of onboard data, so a bad month can be reviewed rather than guessed at.

Predictive control. The current controller samples demand 1,000 times per second and acts on the rate at which demand is rising, not just whether a threshold was crossed. If demand is climbing fast enough to exceed your limit before the interval closes, the system acts first. Older analog load-shedding devices answered one question: is demand above or below the limit right now.

What carries over

On a 9308A, almost everything. The 9308 and 9388 share the same enclosure, relay plate, power transformer, wire harnesses, and CT input. The upgrade is a board-and-display swap and it drops straight in. The box stays on the wall, the relays stay on the plate, the CTs stay clamped on the mains, and the technician replaces the control board and logic cover, then commissions fresh from the front panel. Shortest service call in the line.

On other models, usually the CTs and the wiring. The 9388A expects 200-amp split-core CTs at approximately 1000:1 ratio, and existing CTs matching that description are frequently reusable. That avoids working above the main breaker lugs on an energized service, which is the most time-consuming part of the job. Conduit between the panel and the controller, and the load circuits already run to the old relays, are typically reusable too.

What does not carry over: the enclosure and relay plate on non-9308 models, since mounting patterns differ, and any third-party relays or receivers from Savergy or ZDC equipment.

Send photos of the existing unit with the cover off plus a photo of your panel, and we can usually tell you in advance what the job looks like.

What the service call involves

Duration depends on your existing model and site conditions. A 9308A board-and-display swap is usually the shortest visit.

1. Before the visit. Confirm your utility and rate schedule, and the loads you want controlled. If you added an EV charger, a pool, or a second air conditioner, say so now so the correct relay count is on the truck.
2. Removal and mounting. The old controller comes off. On a 9308A the enclosure stays and only the board and logic cover change.
3. CTs and load connections. Existing CTs are verified for type and orientation, or new ones go on the incoming mains above the main breaker lugs, both facing the same direction. Existing controlled circuits land on the new relays.
4. Commissioning and verification. Time, date, daylight saving off for Arizona, rate selector, relay count, priorities, timing values, and demand range matched to the installed CTs. Instantaneous demand must read non-zero. The technician drops the demand limit to confirm every load sheds, raises it to confirm they restore, and returns it to your operating value.
5. Handoff. Ten minutes on the display, the demand limit, and how to tell it is working. Worth staying for.

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Send a photo of your existing unit and a recent utility bill. Call toll free (888) 461-9336, direct (970) 461-9600, or email help@energysentry.com. Monday–Friday, 8:00 AM–5:00 PM Arizona time.