Control Wiring Services

VRV and VRF depend on programmable logic controllers to optimize air quality and energy costs. That means every part of the system needs to be wired up to a control panel. Lightning Mechanical has experience with control wiring services (also known as System Control Wiring) for all major VRF system providers.

Our technicians and engineers are factory-trained by our partner manufacturers for:

  • Installation
  • Repair
  • Replacement
  • Retrofit

VRF Wiring Design and Installation Services

VRF control wiring is a specialized process. It includes communication, power, and signal wires. The complexity of the connections depends on the number of compressors, fans, heaters, valves, and other components that need to be controlled by the Programmable Logic Controller (PLC). Large systems require communication wires from each component back to the controller panel. These wires configure the operating parameters of each zone. Design and installation of such an array are best performed by a factory-trained installation team.

Lightning Mechanical's technicians have been trained to install wiring for all major VRF system manufacturers, including:


Control Wiring Repair and Replacement

In case of damage or improper installation, replacement becomes a necessity. When control wires become damaged or worn out, replacement is often the quickest and most cost-effective way to get your HVAC system back.

Inspection is required if your property has gone through:

Control Wiring Retrofit

A retrofit is required when wiring for a VRF or VRV system needs upgrading. Retrofitting control wiring can be necessary when control power becomes overloaded, the communication protocol changes, or electronics are changed out.

If your goal is further HVAC automation, you will probably need to re-evaluate your existing systems and associated machinery.

Lightning Mechanical's technicians have extensive experience with all control wiring types and formats across various industries. We've worked with homeowners, businesses, and commercial facilities from New Jersey to Philadelphia and across New York Metro City, ensuring complete satisfaction of technical specifications and clients' needs.

Why Location Matters

When designing your VRF system, we have to pay special attention to where wires can be run. In particular, some wires have to be run from the main panel through to exterior units of your home or business without being exposed to moisture. This can be a challenge in wet and humid climates like in Florida. Control wires require special protection in damp and cold locations like most of the Northern East Coast. For wiring in these challenging environments, special jacketing is needed.

Minimal Structural Intrusion

Installation needs to balance adequate cable protection and minimal interference with your building. Drilling through concrete walls or the ceiling might offer the best protection for your wiring, but it's also a lot of work. To reduce costs and interference with your structure, control wiring can be installed behind the wall panels or inside of the electrical raceways that already exist in most properties.

Your control system also needs to integrate with your existing electrical system seamlessly. Our team will work closely with licensed electricians to ensure your commercial facility, construction projects, or manufacturing plant doesn't suffer any unscheduled downtime.

Lightning Mechanical control wiring technicians have been thoroughly trained to ensure your system wires are installed according to manufacturers' instructions without compromising maintenance accessibility or performance.

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Panel Wiring

Regardless of where control wiring runs, it needs to get back to a control panel. This panel will vary depending on the size of your system and your choice of VRF provider. The panel will need to be wired up to all the following components:

  • A transmission adapter ( so you can access the panel remotely from a computer or your phone)
  • Each indoor terminal unit
  • Every outdoor unit
  • Wired Remote controllers (thermostats in each room)
  • Wireless remote controller receivers (for AC remotes in a room)

The control panel is typically located in a mechanical room, but it's best to ask your control wiring installation team where it's best to place it. Your maintenance providers will need to be able to access it easily.

A transmission adapter will allow you to benefit from complete integration with your BMS system. It also grants access to a suite of automation software and remote monitor technologies most manufacturers offer for their systems.

VRF control panels need to communicate with:

  • Digital control wires – PLC programming instructions, signals for fan speed, or refrigerant valves.
  • Analog machine control wiring – Temperature sensors.
  • Field device machine control wiring – Terminal strip connections for dampers, emergency shutdowns, and pumps
  • Gateway Device – Communication between the control wiring control panel and accessories such as an energy management system (EMS) or building management systems (BMS)

VRF main panels can be wired using Fieldbus protocols, including:

  • Modbus RTU/ASCII RS485
  • Foundation Fieldbus H1
  • Foundation Fieldbus HSE
  • DeviceNet with wiring devices such as a controller or a variable speed drive.
  • Wiring over Ethernet/IP using the LonWorks interface module (CIM)
  • Wiring devices with LonWorks capability.


How Much Does It Cost?

Unlike HVAC wiring, control wiring services for VRF systems are a critical part of the system. It's an intelligent system that allows for high energy efficiency and thus can cost more. However, the initial cost is quickly recouped through utility bill reductions.

The complexity of control wiring installation is proportional to the number of components you need to control with your PLC (Programmable Logic Controller). The more control wires you need to run between components, the more complicated it gets.

Lightning Mechanical can provide control wiring service price quotes after we perform a site inspection and determine the number of control wires your system needs. We are also experienced with manufacturing requirements for electrical control and panel build specifications.



Do You Need It?

VRF wiring is generally installed when your control system includes multiple indoor units. If you only need control wires to be run between one of the outdoor units and the control panel, you can usually get by with a single control wire. However, for services involving more than one control cable, it's best to have a wiring solution designed by professional technicians working with an electrician.


Do You Need to Plan Ahead?

When control wiring is done in advance, it makes installations much easier. This control wiring is commonly installed by the HVAC contractors at the same time as the other control systems your facility needs. This also applies to new construction projects where we coordinate closely with other companies on the job. Our customers can be assured that all of our control wiring services are a measure twice, cut once operation.

If you need control wiring in your facility, our technicians can install it quickly and with minimal downtime to your system.

Control Wiring Services

Types of Wiring

Machine control wiring needs two control power circuits: one positive and one negative. The following cable types are allowed by code for control power in any climate:

Tinned Copper Wiring

Tinned copper wiring is the most appropriate choice for connections that runs under 600 feet. Control wires in conduit or non-metallic control wire trays can be bent at any angle (not more than 180 degrees within 3 feet), making it a fairly versatile option for most installations.

PVC Jacketed

Polyvinyl chloride wiring jackets are made from virgin vinyl-chloride monomer materials with an average molecular weight of 150,000 to 170,000. PVC jackets can be used for control power and control circuits in conduit, cable tray, or directly within a panel enclosure.


Foil-Screened control power wiring is made from oxygen-free high conductivity copper with a minimum of 50 percent IACS electrical conductivity at the time of manufacture. The insulation on this wiring is similar to control power cables. However, control wiring is measured with a 65°C rating.

Shielded Cables

Shielded control power cables consist of insulated wires with power conductors and metallic shields or braids. Shielded control power cables are allowed for control wiring on control panels, control conduit systems, or control wireway systems.

Contact us

Call us on (973) 763-0300 Monday to Fridays between 8 am and 6 pm to find out how to provide custom control assemblies and panel wiring for your VRF or VRV system. You can also email us any time at or

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Contact Us

65 Newark Way, Maplewood, NJ 07040, US
Monday - Friday: 8am - 6pm
24 Hour on call emergency service available