MD controller vs energy monitoring: stop the peak, and know what built it.

What an MD controller does

An MD controller watches demand at the incoming supply, usually through its own CTs or a pulse from the main meter. As each 15- or 30-minute interval runs, it predicts where the average will end. If the prediction crosses the limit you set, it switches relay outputs to switch off or hold back preset loads in a fixed priority order, and releases them once demand falls. Its job is narrow and automatic: keep this interval under the limit.

What an energy monitoring system does

An energy monitoring system reads the multifunction meters on the incomer and on each panel and keeps the history. It shows the running Maximum Demand interval live, but also power factor, voltage, current, energy by hour and shift, TOD split, load factor and an estimate of the bill, and it alerts the team before a limit is crossed. Its job is wider: show which panel built the peak, why the bill went up, and whether a fix worked.

Side by side

Where an MD controller falls short

• It treats the symptom. It holds the peak down by switching loads off, but cannot tell you why the peak keeps coming back or which panel is growing.
• Shed loads cost production. Every trip of a chiller, compressor or furnace is work delayed. If the controller trips often, Contract Demand or the load schedule may be the real problem.
• It sees only demand. Low power factor, idle machines, TOD timing and a rising base load all add to the bill without ever tripping the controller.

Where monitoring alone falls short

An alert needs someone to act on it within minutes. On a night shift, or where the same loads should always be held back, an automatic action is more reliable than a person. That is where demand control earns its place. KONDUKTOR® EMS adds it through Modbus I/O cards, so you do not need a separate controller.

Which does your plant need?

• The bill is high and nobody knows why: start with monitoring. Most of the money is usually in power factor, idle load, TOD timing and Contract Demand, not only in the peak. See reduce factory bill.
• MD crosses Contract Demand often, from loads that can safely wait: you need automatic control, and monitoring to choose the right loads and limit.
• You already have an MD controller: monitoring shows how often it trips, what it costs in production and whether Contract Demand needs revising. See Contract Demand.

How KONDUKTOR® EMS handles demand

• The running Maximum Demand interval on every meter, live, against Contract Demand, with alerts as it approaches the limit.
• Monthly Maximum Demand history with the date and time of each month’s peak.
• Demand per panel, so you see which load built the peak.
• Where loads should be held back automatically, Modbus I/O cards switch off or delay chosen non-essential loads as the running interval nears the limit. This is engineered for your plant as part of your project, with the loads, priorities and limits agreed with your team. Because it sees every panel, you choose those loads from what actually builds the peak.

See seven ways to reduce Maximum Demand and the cost of one spike in the MD penalty calculator.

Want automatic control? See how the Maximum Demand controller works. Weighing up a bigger system? See EMS vs SCADA vs BMS.