Energy Sentry model library

Current production

Four models share the same control algorithm and the same operating principle. They differ in service type, capacity, and how they reach the loads they control.

Shared across the line: approximately 1000:1 current transformer ratio, 1,000 demand samples per second, sliding-window averaging matched to the utility's interval, roughly three months of onboard operational data, NEMA 3R raintight enclosure on residential and light commercial units, and a 3-year warranty.

9388A — Residential

The standard product for homes. Split single-phase 120/240V service, up to 40 kW. Ships with two 30-amp power relays on the relay plate and two low-voltage relay outputs on the board, in a grey NEMA 3R raintight enclosure with a left-side hinge. There is room on the relay plate for up to six power relays, so additional control points are a parts change rather than a different unit.

Typical Arizona configuration controls the dryer heating element, one or two air conditioners through a 50-amp latching relay, and the water heater. Pool pumps, spa heaters, EV chargers, and electric heat are added as the site requires.

For what a residential install includes and how a quote works, see Shop.

9388B — Light commercial

Same controller, three-phase service, up to 80 kW. The difference that matters is power line carrier. The 9388B drives a PLC transmitter through a bus connector, which sends a 270 kHz control signal over the building's existing copper wiring to receiver modules mounted at each load. Effective range is about 2,000 wire feet.

That is what makes commercial work practical. Instead of pulling dedicated control wire across a building to six rooftop units, the installer mounts a receiver in each unit's electrical compartment and the signal travels on wire that is already there.

This is the workhorse for churches, small offices, retail, restaurants, and light industrial.

9388C — Large commercial

Up to 1 MW. Eight or sixteen low-voltage relay outputs and no PLC transmitter. Designed for facilities where the electrical contractor is already running control wiring to motor starters, contactors, and building automation points, and simply needs dry contacts to interface with.

9388M — Industrial

Up to 10 MW, extendable to 20 MW through software configuration. Functionally identical to the 9388C. The hardware does not change; the scaling does. Used on industrial plants, large agricultural operations, and multi-building campuses on a single meter.

Legacy models

These are no longer produced. Many are still running. We still answer the phone about all of them.

About the 9200 series

The 9208A and 9288A carried the first major rewrite of the demand control algorithm. The original code dates to the mid-1980s; the 9200 series is where it was rebuilt. Those units still hold demand well. What they cannot do is follow current utility rate schedules. Rate plans have changed repeatedly since these shipped, and the season definitions, holiday calendars, and averaging periods burned into a 9200-series unit no longer match what your utility is billing. That mismatch, not a hardware failure, is the usual reason a 9200-series unit stops saving money.

About the 9300 series

The 9300 series moved to a more capable processor, which allowed further refinement of the algorithm. The 9308A is the direct predecessor to the 9388A.

Important for anyone quoting a 9308A upgrade: 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 drops straight in. You keep the box on the wall, the relays, the transformer, the harnesses, and the CTs already clamped on the mains. The technician replaces the control board and logic cover and commissions the unit fresh from the front panel. It is the least invasive upgrade in the line. See the upgrade path page for full detail.

About the 9320 monitors

The 9320 series measured and displayed demand. It did not control anything. If you have a 9320 on the wall, you have been watching the problem, not solving it. Any of the current controllers replaces it and adds automated load control on the same CTs.

About Savergy and ZDC units

Savergy SC104 and SC208 controllers, and ZDC SC-series controllers, show up regularly in homes and small commercial buildings. Neither line is supported by its original manufacturer. We do not stock parts for them. What we can do is replace them with a 9388A, and in most cases the existing CTs and conduit runs are reusable, which keeps the service call short.

One note that comes up on ZDC replacements: some ZDC units had no low-voltage relay outputs, so heat pumps were switched with a power relay whether or not that was appropriate. The 9388A has two low-voltage outputs on the board, which usually means a cleaner and cheaper configuration after the swap.

Identifying what you have

The model number is on the UL label on the outside of the enclosure cover and on the serial number label attached to the relay plate inside. On powered units, the display shows FE followed by the firmware version for a moment at power-up.

If the label is gone or unreadable, send us a photo of the unit with the cover off and we will identify it. Most of these we can name on sight.

---

Questions about your unit? 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.