Testing, Startup & Final Power

Before permanent power is introduced, OTC verifies applicable portions of the installation for conditions such as:

• Equipment connections

• Conductor terminations

• Grounding and bonding

• Breaker installation

• Panel configuration

• Equipment labeling

• Feeder routing

• Required covers and hardware

• Visible installation deficiencies

The exact verification process depends on the equipment and project requirements.

The goal is to identify problems while the system is still in a controlled pre-energization condition.

Permanent power typically requires coordination between several parties.

Depending on the project, that may include:

• Utility provider

• AHJ

• Electrical engineer

• General contractor

• Equipment manufacturer

• Testing agency

• OTC electrical team

Before the utility energizes the service, required inspections, equipment, and site conditions need to be complete.

OTC coordinates the electrical construction requirements leading up to final utility energization.

Large commercial electrical systems should not simply be energized all at once without a plan.

Startup may progress through equipment such as:

Service Equipment → Main Distribution → Transformers → Panels → Branch Circuits → Final Loads

OTC works through the electrical system systematically so problems can be identified at the appropriate level instead of energizing the entire building and then trying to determine where an issue originated.

Once the system is energized, OTC can verify applicable electrical conditions including:

• Phase-to-phase voltage

• Phase-to-neutral voltage

• Transformer output

• Phase rotation where equipment requires it

• Panel voltage

• Equipment supply voltage

This is especially important for:

• Three-phase motors

• HVAC equipment

• Pumps

• Compressors

• Machinery

• Other phase-sensitive equipment

Correct voltage at the service does not automatically prove the correct voltage is reaching every piece of equipment.

Transformers are verified as part of the distribution startup.

Depending on the system, OTC may confirm:

• Primary voltage

• Secondary voltage

• Phase

• Connections

• Grounding

• Downstream distribution

The transformer and downstream panels need to operate together as one electrical system before branch loads are placed into service.

Final lighting startup can include verification of:

• Fixtures

• Switching

• Occupancy sensors

• Dimming

• 0–10V controls

• Daylight controls

• Photocells

• Time clocks

• Contactors

• Exterior lighting

• Emergency lighting

A fixture turning on does not necessarily mean the control system is functioning as intended.

OTC verifies the applicable lighting sequence so the finished system operates according to the project design.

Commercial equipment is often started and commissioned by the equipment manufacturer, mechanical contractor, controls contractor, or another specialty vendor.

OTC supports that startup by verifying the electrical side of the installation.

That may include:

• Correct voltage

• Phase

• Circuit availability

• Breaker operation

• Disconnects

• Equipment feeder

• Power at the final connection

If equipment does not start correctly, the electrical supply can be checked before assuming the equipment itself is defective.

Backup-power systems should be functionally tested as a complete system.

Depending on the project, testing may verify:

1. Normal utility power

2. Utility-power loss

3. Generator start

4. ATS transfer

5. Critical distribution energization

6. Operation of supported loads

7. Return of utility power

8. Retransfer to normal source

The generator starting by itself does not prove that backup power reaches the required equipment.

Some projects require specialized testing of major electrical equipment.

Depending on the engineer, specifications, manufacturer, or AHJ, this may include testing of equipment such as:

• Switchgear

• Breakers

• Large feeders

• Grounding systems

• Protective devices

• Other major distribution equipment

Where specialized acceptance testing is required, OTC coordinates with qualified testing agencies and the project team.

Testing methods are selected based on the actual equipment and project requirements rather than applying the same test to every electrical system.

Electrical closeout should leave the building easier to operate and maintain.

OTC completes applicable labeling for:

• Panels

• Circuits

• Disconnects

• Transformers

• Equipment

• Critical-power systems

Panel schedules should identify what the breakers actually serve.

Accurate labeling saves time during future maintenance, troubleshooting, shutdowns, and tenant improvements.

Before final turnover, OTC works through remaining electrical punch-list items.

That may include:

• Device corrections

• Fixture adjustments

• Labeling

• Missing covers

• Control issues

• Equipment connections

• Panel-directory corrections

• Final testing

• Inspection corrections

The objective is to close out the electrical scope rather than leave small unresolved items for the owner to discover after occupancy.

Electrical turnover may include applicable:

• Panel schedules

• Equipment documentation

• Test information

• Photos

• Approved changes

• Closeout information

• Remaining recommendations

The finished building should not only have power.

The owner and facility team should be able to understand the electrical systems they are receiving.