Thunder Bay Hydro Coporation

Serving the City of Thunder Bay with electricity.

New Commercial Service

Home > Business > New Commercial Service

Guidelines for Acquiring Electrical Service

If you are building or renovating a business in the City of Thunder Bay and require a new or upgraded service, the process you follow depends on the size of the service you are having installed.

If your service is to be less that 200 Amps, you follow the same six steps as a residential customer.

Services under 200 Amps

If your service is to be 3Ø 200-amps or greater and 1Ø greater than 200-amps, the following 12 steps need to be completed for this process:

Click here for a PDF version

Step 1 - Read Our Conditions of Service

As a first step, we recommend you read the Thunder Bay Hydro Conditions of Service. Print copies are also available at our Power Systems building, located at 37 Front Street. 

Step 2 - Meet with Design Technician/ Technologist

Set up an appointment with a Distribution Designer to discuss the requirements of your new or upgraded electrical service and where it should be located. Call our Engineering Services Department at 343-1168 to make arrangements.

Step 3 - Provide Information

The Designer will require you to provide the information listed on the Service Information Sheet (formerly the Transformer Information Sheet). Information required will include, but not be limited to:

  • Dimensioned project layout drawings showing electrical installations. Transformer foundation installation to be shown as per Thunder Bay Hydro Standard 37-371. Duct runs to be shown using 4“ type DB2 PVC at 40” depth with 6” sand bed above and below. Marker tape to be shown 1' down from grade. Pull rope to be in duct. The contractor will be asked to provide a signed copy of this project drawing declaring that the installation complies with the drawing.
  • All service and load data
  • Shop drawings for the service entrance and metering equipment, which must comply with Thunder Bay Hydro  Standard 25U-160, 25U-162, 25U-164, or 25U-166. All service entrance and metering equipment must meet Thunder Bay Hydro's Engineering Standards (available from the Design Technician/Technologists). Please note that all service entrance equipment (except the main breaker, which must be sealable) up to and including the meter cabinet must have hinged and lockable doors. Meters shall be mounted to be centered 5' 6” above the floor. Meter sockets must be approved by the Designer prior to installation. Services over 600-amp must have the bus bar out from the main breaker for CT mounting.
  • Grounding design (ground resistance to be 8 ohms maximum)
  • The quantity of meters required for the service 

Note that customers requesting a service over 50kW are required to install interval metering. A telephone line must be supplied to the meter base at the owner's expense before the service is energized. If the telephone line can not be installed before Thunder Bay Hydro energizes the service, additional charges to manually read the meter once a week until the telephone line is installed will be added to the cost of the job and will be reflected when the true-up of costs has been completed.

Once you have provided all information deemed necessary by the Designer, we will proceed with reviewing your electrical service. 

Step 4 - Estimate to Connect

After reviewing all your information and finding the details acceptable, the Designer will complete a Thunder Bay Hydro Estimate to Connect Overhead & Underground Distribution form or a" Thunder Bay Hydro Estimate to Connect Commercial Customers and Customers Over 200 Amp" form. This document will include the estimated cost of the labour and materials supplied by Thunder Bay Hydro to install/upgrade the service. The Estimate to Connect can be directed to the property owner or an authorized representative for the property owner. 

This Estimate to Connect must be paid in full before Thunder Bay Hydro can proceed with any work. Once the work is completed, a 'true-up' will be completed and the customer will be billed for actual costs.

After the Estimate to Connect is issued:

  • We will officially communicate with the person named on the Estimate to Connect. Unofficial communication may take place with others, but any directives required either way will be between the person named on the Estimate to Connect and the Distribution Designer.
  • The person named on the Estimate to Connect will receive an invoice from our Finance Division within one week, detailing the cost to have Thunder Bay Hydro complete the required work to connect/reconnect the new or upgraded service. 

Step 5 - Make Payment

The invoice, based on the Estimate to Connect, will need to be paid in full before Thunder Bay Hydro can proceed with any work on the electrical service. Payment can be made two ways:

  • Through mail by forwarding a cheque or money order to our Accounting Department, 34 N. Cumberland Street, P7A 4L4, or
  • In person* at our Accounting Department, on the 8th floor of 34 N. Cumberland Street (between 8 am to noon or 1 pm to 4 pm weekdays) using VISA or MASTERCARD credit card. DEBIT card option is also available.

*no telephone credit card payments will be accepted.

Step 6 - Changes, If Required

If, after the Estimate to Connect is issued, you require changes to the work to be done by Thunder Bay Hydro, the actual costs to revise the drawing will be charged to the customer and will be reflected in the true-up when the work is completed.

Step 7 - Contact the ESA

Either you or the contractor doing the electrical work must contact the Electrical Safety Authority (ESA) at 1-877-372-7233 to obtain an electrical permit.

Step 8 - Arrange Inspections

Three preliminary inspections and one final inspection must be performed by Thunder Bay Hydro. These are separate from the ESA inspection, which is also required. It is recommended that you request the Thunder Bay Hydro preliminary and final inspections before the ESA inspection to avoid having to request ESA re-inspection should Thunder Bay Hydro require modifications.

  1. The first Thunder Bay Hydro preliminary inspection is required after the gravel bed is prepared for the transformer foundation.
  2. The second Thunder Bay Hydro preliminary inspection is required after the transformer foundation and ducts are installed in accordance with Thunder Bay Hydro Standard 37-371.
  3. The third Thunder Bay Hydro preliminary inspection is required after the ground grid is installed.
  4. Thunder Bay Hydro will then measure the ground resistance.


Step 9 - Ground Resistance Testing

  The cost of one ground resistance reading test is included in the amount quoted on the Estimate to Connect. If ground resistance testing results in readings over the maximum 8 ohms, actual costs for each additional test required until the readings are at or below 8 ohms will be added to the cost of the job and will be reflected when the true-up of costs has been completed.

Step 10 - Thunder Bay Hydro Final Inspection

When the contractor has completed the electrical service you or your authorized representative must notify the Designer that the electrical service is available for Thunder Bay Hydro final inspection. Both Thunder Bay Hydro and ESA inspections need to be completed satisfactorily and payment must be received in full before we will be able to connect/reconnect the new or upgraded service. Note that the cost for additional inspections by the Designer or any additional work that is required by Thunder Bay Hydro staff will be added to the cost of the job and reflected in the true-up.

Step 11 - Set Up Thunder Bay Hydro Account

If this is a new service, you will need to set up an account at our Customer Accounts Department, located on the main floor at 34 N. Cumberland Street. Call 343-1111 for more information.

Step 12 - ESA Final Inspection

When the electrical work is complete and has been approved by Thunder Bay Hydro, contact the ESA to arrange for an inspection.

When the ESA Inspector's authorization is received, our Customer Accounts Department will prepare a service connection order for each meter. These orders are forwarded to our Engineering Services Department. Once Thunder Bay Hydro has completed the necessary line work and the inspection has been completed and approved, the new or upgraded service will be connected within 10 working days