Planning a generator purchase and trying to understand your building’s needs? A meter reading can contribute to the assessment. If a DMW display is available, it must be interpreted using information for the exact meter.
How can DMW help?
The CMEQ mentions meter DMW among the information used to assess available electrical capacity. This reference concerns the electrical installation; it does not provide a formula to convert a reading directly into generator capacity. Source: CMEQ, Électricité Québec, May–June 2025.
Distinguish power from energy
Power, measured in kilowatts (kW), and energy, measured in kilowatt-hours (kWh), describe different things. An appliance drawing 1 kW for 2 hours uses 2 kWh. A bill’s total energy consumption alone therefore does not identify the power required when several appliances run together. Hydro-Québec explains these power concepts.
What meter information should you record?
If DMW appears, photograph the value with its unit and record the date. Also note the meter brand and model. Confirm what the display means, the period it covers and any resets. Do not assume it automatically represents the previous 12 months.
Cannot find DMW? Gather the information available in your Hydro-Québec account and a list of essential appliances. Preparing an inquiry does not require manipulating the meter or opening electrical equipment.
Why is the reading not enough?
Some motors and compressors require more power to start. Simultaneous starting and the load recovery sequence also affect sizing. A historical reading does not replace an assessment of these loads. Source: Cummins, T-030 application manual, chapter 3.
Also identify equipment added since the reading and what you actually want to keep running during an outage. Supplying essential circuits and backing up an entire building are different projects.
Prepare your inquiry step by step
- Include the reading, unit, date and meter model if available.
- List appliances that must run simultaneously.
- Add clear photographs of their nameplates.
- Specify voltage and phases when known.
- Mention planned changes: heating, pumps, refrigeration or production equipment.
For the general method, read our generator sizing guide. Then have sizing and connections validated by the professionals responsible for the project.