Contactors & Control Wiring
When most people think about commercial electrical work, they think about breakers, panels, conduit, receptacles, and large electrical equipment. But behind many commercial buildings is another layer of electrical work that determines when equipment turns on, what turns it off, what equipment operates together, and what happens when an emergency condition occurs.
That is where contactors and control wiring come into the picture.
At Pinellas County Electric, we install, troubleshoot, replace, and modify contactors and electrical control wiring for commercial properties throughout Clearwater and Pinellas County. These systems can be used for everything from parking garage lighting and commercial kitchens to access control, exhaust systems, pumps, equipment shutdowns, lighting control panels, and power distribution.
One thing I learned a long time ago is that supplying power to a piece of equipment is only part of the job. In a commercial building, we often also need to answer another question:
What is supposed to control that power?
Key Takeaways
Contactors and control wiring allow commercial electrical equipment to operate automatically, remotely, on a schedule, or as part of a sequence with other equipment. A relatively small control signal can operate a contactor that switches a much larger electrical load. Depending on the application, that control signal might come from a timer, photocell, switch, relay, access control system, lighting controller, fire suppression system, building control, sensor, or another piece of equipment.
Pinellas County Electric works with contactors and control wiring for commercial kitchens, parking garages, exterior lighting, lighting control panels, access control systems, mechanical equipment, pumps, exhaust and makeup air systems, power distribution, and specialty commercial equipment.
The important part isn’t simply making the equipment turn on. The control system needs to make the equipment operate in the correct order, under the correct conditions, and shut down when it is supposed to.
What Is a Contactor?
A contactor is essentially an electrically controlled switch designed to control another electrical load.
Instead of having someone manually switch a large electrical load every time it needs to operate, a smaller control circuit can energize the contactor. The contactor then opens or closes its contacts and controls the larger load.
This becomes extremely useful in commercial applications because we can separate control power from equipment power.
For example, a lighting contactor might control several large lighting circuits while a small timer or photocell tells that contactor when those lights should turn on.
The same basic principle can become much more sophisticated when we start incorporating relays, normally open and normally closed contacts, timers, sensors, emergency shutdowns, and other control devices.
Control Wiring Allows Equipment to Work Together
This is where I think customers begin to understand why control wiring is so important. Sometimes a customer will show me a piece of equipment and ask: “Can you get power to this?” Usually, we can. But then I start asking questions.
- What turns it on?
- What turns it off?
- Does something else need to be running first?
- Does another piece of equipment need to shut down when this starts?
- Is there an emergency stop?
- Is there a fire suppression system involved?
- Does it operate from a timer?
- Is there an access control system?
- Does somebody need to operate it remotely?
Those questions can completely change the electrical installation.A commercial electrical system doesn’t always consist of individual pieces of equipment operating independently. Sometimes the building needs those systems to communicate and operate in a particular sequence.
That’s what properly designed control wiring allows us to accomplish.
Commercial Kitchen Equipment & Control Wiring
Commercial kitchens are a perfect example. I’ve walked into kitchens where someone thinks we’re simply connecting power to an oven, fryer, hood, exhaust fan, makeup air unit, dishwasher, steamer, or another appliance. Then we start looking at everything that equipment is connected to.
A commercial hood and fire suppression system may need electrical equipment underneath the hood to respond in a particular way when the suppression system activates. Depending on the approved system design, normally open and normally closed contacts, relays, contactors, or other control methods can be used to initiate the required equipment shutdowns and operating sequence.
The exhaust system, makeup air, cooking equipment, gas controls, alarms, and other components may all have specific requirements. That’s why I don’t like guessing with commercial kitchen controls.
We determine what the approved system requires, identify the sequence of operation, and then wire the controls accordingly.
Parking Garage & Exterior Lighting Controls
Parking garages are another area where contactors can make a tremendous amount of sense. Think about the amount of lighting that can exist in a parking garage, parking lot, building exterior, canopy, walkway, or common area.
You don’t necessarily want someone walking around manually turning dozens of circuits on and off every morning and evening.
A properly designed lighting control system can use contactors, photocells, astronomical time clocks, occupancy sensors, lighting control panels, or combinations of these devices to control larger groups of lighting.
The system can be designed so that different areas operate differently.
Maybe certain security lighting remains on throughout the night. Other lighting may operate from dusk until a predetermined time. Additional lighting might activate based on occupancy or another control input.
Instead of simply asking, “How do we turn these lights on?”, I like to ask: “How do you actually want this property to operate?” That conversation can lead to a much better electrical system.
Lighting Control Panels
Commercial lighting controls can range from something relatively simple to a much larger building wide system.
We’ve worked around buildings where lighting is controlled through contactors and relays rather than every lighting circuit being controlled directly from a wall switch. That gives a business considerably more control over how the property operates.
Depending on the equipment and design, lighting can be separated into zones, controlled by schedules, operated by occupancy, controlled from centralized locations, or integrated with other building systems.
Low voltage control wiring can also allow switches and control devices to command lighting equipment without requiring the entire lighting load to pass through the wall switch itself.
For larger commercial properties, that can create a much more organized way to manage the building.
Door Access Control & Electrified Doors
Access control is another area where power and control wiring come together. Commercial doors can incorporate electric strikes, magnetic locks, request to exit devices, door position switches, keypads, card readers, power supplies, relays, push buttons, and access control panels.
But there is an important distinction here. Getting electricity to a door is only part of an access control installation. We also need to understand what is supposed to happen when somebody presents a credential, what releases the door, what happens during loss of power, and what life safety requirements apply to that opening.
Depending on the system, different trades and system providers may be involved. Our responsibility on the electrical side is to make sure the power and control portions within our scope are installed correctly and coordinated with the access control and life safety requirements of the project.
When doors involve emergency egress or fire alarm interfaces, the approved design and applicable life safety requirements take priority over convenience.
Contactors in Power Distribution
Contactors aren’t limited to lighting and small controls. They can also be incorporated into larger commercial electrical distribution and equipment control systems.
A contactor may control a single piece of equipment, multiple circuits, a motor load, lighting system, heating load, pump, exhaust system, or another electrical load.
This is where proper equipment selection becomes extremely important.
We need to know the voltage, phase, amperage, load characteristics, contactor rating, coil voltage, control voltage, number of poles, auxiliary contacts, enclosure requirements, and what is actually commanding the contactor.
A contactor that physically fits in an enclosure doesn’t automatically mean it’s the right contactor for the application.
Normally Open & Normally Closed Contacts
Two terms you’ll hear constantly when dealing with control systems are normally open and normally closed. The easiest way I explain this is to think about what the circuit is doing when the control device is sitting in its normal state.
A normally open contact starts open and closes when activated. A normally closed contact starts closed and opens when activated. Once you understand that basic principle, you can begin creating control sequences.
A device activating might cause one piece of equipment to turn on while simultaneously causing another piece of equipment to turn off. That’s how relatively simple control components can create surprisingly sophisticated commercial systems.
Troubleshooting Contactors & Control Wiring
Control problems can also be some of the more interesting electrical problems to troubleshoot.
I’ve been on jobs where someone says: “The equipment doesn’t have power.” That doesn’t necessarily mean the equipment lost its electrical feed.
The breaker could be perfectly fine. The equipment might be waiting for permission to operate. That’s where I start tracing the control side.
- Is the contactor pulling in?
- Does the coil have the correct voltage?
- Is a normally closed contact open somewhere?
- Did a timer fail?
- Did a photocell fail?
- Is there a control fuse?
- Is an emergency stop activated?
- Is another piece of equipment supposed to provide an enable signal?
- Is a relay working?
- Is there a loose control conductor?
Sometimes the difference between replacing expensive equipment and repairing a control problem comes down to understanding the sequence of operation.
I don’t want to start replacing parts until we understand what the system is supposed to be doing.
Understanding the Sequence of Operation
This may be the most important part of commercial control troubleshooting. Before I start changing things, I want to understand:
What is supposed to happen first? Then what? And what happens after that? If we don’t understand the sequence, it’s easy to find one component that isn’t operating and assume that component is bad.
But maybe it’s not supposed to operate yet. Another control may not have given it permission. That’s why drawings, equipment specifications, wiring diagrams, control diagrams, and conversations with the equipment manufacturer can become extremely valuable.
Good troubleshooting isn’t just finding what isn’t working. It’s understanding why it isn’t working.
Control Wiring Can Make a Commercial Building More Efficient
Efficiency doesn’t always mean reducing the electrical consumption of a single piece of equipment. Sometimes efficiency means not operating equipment when it isn’t needed.
Parking lot lighting doesn’t need to operate during the middle of a sunny afternoon. Certain ventilation equipment may not need to operate continuously. Different areas of a commercial building may have completely different schedules.
Controls allow the building to respond to those conditions automatically.
That can reduce unnecessary operating hours, reduce wear on equipment, simplify building operation, and give property managers greater control over their electrical systems.
For businesses with multiple buildings or large facilities, those improvements can become significant.
Contactors & Commercial Control Wiring FAQs
What does a contactor do in a commercial electrical system?
A contactor allows a smaller control circuit to switch a larger electrical load. Contactors are commonly used for lighting, motors, pumps, mechanical equipment, commercial kitchen systems, and other electrical loads that need automatic or remote control.
Can Pinellas County Electric troubleshoot an existing control system?
Yes. We can troubleshoot the electrical and control wiring within our scope, including contactors, relays, timers, photocells, switches, control power, and related wiring. One of the first things we’ll try to determine is the intended sequence of operation.
Can contactors automatically control parking lot and parking garage lighting?
Yes. Depending on the design, contactors can work with photocells, timers, astronomical clocks, occupancy controls, lighting control panels, and other devices to automatically operate commercial lighting.
Do commercial kitchens use contactors and control wiring?
Very often. Commercial kitchens can have electrical interlocks involving cooking equipment, exhaust systems, makeup air systems, fire suppression systems, and other equipment. The exact sequence depends on the approved kitchen and fire suppression design.
Can you install control wiring for commercial access control?
We can provide electrical power and control wiring within our licensed scope and coordinate with access control, fire alarm, door hardware, and other system providers when necessary. Electrified doors must also maintain the required life safety and emergency egress functions.
Service Areas
- Pinellas County Electric provides commercial contactor installation
- Control wiring, electrical troubleshooting
- Lighting controls
- Equipment controls
- and commercial electrical services throughout Clearwater
- Clearwater Beach
- St. Petersburg
- Largo
- Pinellas Park
- Safety Harbor
- Dunedin
- Palm Harbor
- Tarpon Springs
- Seminole
- Belleair
- Belleair Beach
- Indian Rocks Beach
- Indian Shores
- Madeira Beach
- Redington Beach
- Redington Shores
- North Redington Beach
- Treasure Island
- Gulfport
- Oldsmar
and surrounding communities throughout Pinellas County.
Need Better Control of Your Commercial Electrical System?
Sometimes the problem isn’t getting electricity to the equipment. It’s controlling what that electricity does once it gets there.
At Pinellas County Electric, The Panel Pros™, we work with commercial property owners, facility managers, restaurants, contractors, HOAs, and businesses to install and troubleshoot contactors and control wiring throughout Pinellas County.
Whether you’re trying to automatically control a parking garage, coordinate commercial kitchen equipment, power an access control system, operate exterior lighting, troubleshoot an existing contactor, or develop a better sequence for several pieces of equipment, show us what you’re trying to accomplish before you start buying parts.
We’ll look at the power requirements, the controls, and most importantly, how everything is supposed to work together.
Pinellas County Electric, The Panel Pros™ Commercial Contactors & Control Wiring Clearwater & Pinellas County, Florida 727-269-1982
