MH Controls Corner: Integration with Lighting Controls

Most lighting control systems on the market today are advertising seamless integration with other building systems. Lighting controls are integrating with Building Automation Systems (BAS), temperature control systems, fire alarm systems, security systems, and others. Integration has great promise to enhance the built environment, and is advertised to operate flawlessly. However, in practice, the reality of these new technologies, once implemented, can be considerably different. To get the most out of these systems, it is necessary to balance the actual needs of the facility and operations with the complexity of the systems. The more complex the system becomes, more potential exists for operational problems that will limit the usability of the system.

Many project designs include specifications requiring that the lighting control system have the ability to integrate with other systems. However, rarely is there definition as to what the integrated systems are to accomplish. Stating that a system is required to be BACnet, or otherwise capable for integration, is not enough to define the necessary hardware. Design guidance dictating how the integrated systems operate will enable the selection of correct components to meet the need. In most cases today, integration requirements are determined during the construction process as an after-the-fact, ad-hoc collaboration between multiple contractors. During design, the owner needs to be involved with the engineering team to define what the systems will do, and how they should work. When looking at system operations, the capabilities of the facilities staff is another important consideration. Overly complex systems that are difficult to operate defeat the intent of integration.

Most common on projects is the need to integrate the lighting control system with the BAS or temperature control system. There are multiple ways to accomplish this integration. The optimal design comes from what the system needs to do. Building in additional complexity to the system reduces the reliability. For example, providing full BACnet connectivity is unnecessary if the goal is to schedule a couple circuits worth of outdoor lighting from the BAS system. Dry contact connections from the BAS system to the lighting control system will be easier to implement and more reliable.

The following are the most common integration operations used by facility owners. Recommendations for the most cost effective and reliable method of accomplishing each integration are included.

1. Controlling Lighting Through Time Schedules Programmed via the BAS - Best practice for this operation depends on how many zones or circuits of lighting control are required. If there are just a couple zones of control required, it is easiest to have a dry contact output from the BAS to a dry contact input on the lighting control system per zone. Zones may include multiple relays or other distributed lighting controls. When defining the zones controlled by the BAS, it is important to consider how many zones are necessary. Each area that will operate on a different schedule requires a control zone. Use groups of zones where there are independent manual controls in different zones that will also have the same time schedule. If there are more than a few zones necessary, networked BACnet or other communications are used.

2. Controlling Variable Air Volume (VAV) Temperature Controls Based on Occupancy of Particular Spaces - The best practice is to include a dry contact output from the local occupancy sensors to a contact input to the VAV in the space. No network connections are necessary. If BACnet or other networked connections are used, the lighting control system communicates the occupancy data to the front end of the BAS system that then communicates with the temperature control system back in the space where the lighting controls are located. This added complexity will reduce the reliability of the system.

3. Larger Scale Integration of Mechanical, Lighting, and Other Systems - The goal of this level of integration is to have full control and feedback from all systems at one central location. Often, these network systems will include energy metering, load shed capabilities, and other advanced capabilities. Custom graphical maps of the facility may also be included. For this scale of integration, a communications protocol connecting multiple systems and every lighting control device will be required. Integration of the different systems requires technicians from each system to work together to make the systems talk to each other. An integration specialist that fully understands the facility owner’s objectives will lead this process between the technicians of the separate systems. This integrator also typically provides the programming necessary for the front-end user interface of the integrated system. Since this approach can be very costly, only add it to a project if it will support the business of the facility owner.

When specifying an integrated system design, provide direction for the objectives of the integration. Base the objectives on what the facility operators need instead of attempting to give them everything possible. Providing overly complex systems will greatly increase the cost of the system, and will reduce the reliability of day-to-day operations. Unneeded complexity also increases the maintenance costs for the life of the facility. Simply stating that a lighting control system must be BACnet compatible without any definition as to what the compatibility will be used for only increases the cost of the controls system while providing no benefit to the facility operators.

If any assistance is needed on this topic, or any other lighting controls related topic, don’t hesitate to contact the lighting controls team at The MH Companies! And remember, whenever you have a technical controls question on any project or application, simply email controls@mhlighting.com. This email address is monitored by our entire controls team. During our normal business hours, we are committed to a four-hour response time for all emails sent to this email address!

This article was written by Clint Conley, our Lighting Controls Department Manager. Clint can be reached at 720.904.8554 or clint@mhlighting.com.