The Ins and Outs of Gates
“The real basic gate operator 101 is a motor with some control circuitry in it,” says Richard Sedivy, director of marketing, DoorKing, Inglewood, Calif. “It relies on input from an access control device, card reader or radio transmitter that tells it to open. Typically, once a vehicle has cleared, the gate closes, and gate operators know this because there are loops in the ground, or the timer times out and closes the gate.”
A circuit board provides the “brains of the operator,” adds Ron Swartz, customer service/sales representative, Apollo Gate, San Antonio.
“In the projects we see, the typical systems are going to be some kind of support mechanism on the fence gate, whether it’s a rail and tracks or a wheel mechanism or a hinge point that has been reinforced to accept a mechanical push to open or close a gate,” says Kenneth Grant, director of client relations, Universal Safety Response (USR), Franklin, Tenn. “From there, you get the operator itself. Typically this is a self-contained unit that will have a pump with an electric motor to pressurize a hydraulic system to physically slide or swing a gate open and closed.”
Other systems use all electric power, adds William Gioia, marketing manager, gate operator products and access control, The Chamberlain Group, Elmhurst, Ill. “Perimeter control systems are made up of the physical gate opener itself, which might be as basic as an AC or DC motor drive system that physically opens and closes the gate. But it’s more than that, because you want to marry it to an access control device that is appropriate for that type of application. There are a lot of components that go into a gate operator.”
The Three Types of Gates
The barrier arm gate is a parking device, typically not designed to physically keep anyone or any vehicle out, but more to serve as a reminder to stop when required.
Operator Specifics and StandardsWhen it comes to gates and operators, one size definitely does not fit all. There is a lot of information to gather before choosing the right operator.
“There are a great many differences in gate operators,” Gioia says. “From the size and rating that they are capable of handling to the number of cycles, to major design differences, to AC, DC or hydraulic. There are also differences in interface capabilities that they have to work with different access control or security systems.”
Some experts recommend choosing the gate first.
“Knowing the gate is where everything starts,” Gioia says. “You need to know the physical gate itself, the size, the weight, the number of cycles. And you need to anticipate future needs as well. Say a gated community wants you to select a gate operator and they know they are going to grow in size. The number of cycles per day may double in five years. You need to specify the proper size hardware, gate operator, and possibly battery back up.”
Others suggest starting at the operator.
“The operator should come first,” says Brent Nichols, owner, Picasso Gate, an integrator based in Cheyenne, Wyo. “When you look at an application you need to determine the number of cycles; the length and weight of the gate; post construction; is the gate strong enough? Decide which operator to use. At that point, start determining how you are going to apply this gate operator to the gate.”
Regardless of where you begin, the operator must be carefully chosen, Luker adds. “The specifications of the operator capacity should match or exceed the gate construction. The gate operators are specified in how long a gate is and how heavy a gate is. For example when you look at a gate, a professional will say that gate is 12 feet long and 600 pounds, so you need to select an operator with capacity greater than that.”
Talking to the operator manufacturers and even the fence gate manufacturers to get the specific requirements and recommendations can be a good way to determine what size operator you need for an application.
“Most manufacturers will show you a duty cycle or expected cycles per hour for that operator so you can get a good idea,” Gioia says. “Sometimes people under spec the proper operator for the gate.”
On the flip side, however, you don’t want to specify a gate that is too big, either.
“They all provide largely the same function, but you will see differences in the weight of the gate, speed of operation, things like that,” Grant says. “They are scaled to ensure that you can apply the most economical operator to the fence you need, so you are not overbilling small gates with a heavy-duty operator.”
Other factors to consider can be the various features different manufacturers offer.
“Each manufacturer has its own control board,” Sedivy says. “Some manufacturers have some unique things that others don’t have. For example we make a product line that doesn’t use limit switches. We use microprocessors that know exactly how long the gate is. That makes it easier to install and eliminates adjustments for chain stretch.”
Linear simplifies things for the installer by using a universal control board that is the same through the entire product line, Luker says. “If you can work on one board and set it up, you can work on all boards of that same type.”
Bob Dobson, director of new product development for Linear adds: “Universal control allows a dealer to know how to configure a type of gate for a wide variety of applications.”
The Chamberlain Group focuses on bundling its gate operators and access control products. “It’s a matched bundle so you know that you will get access control that works with the gate, the entrapment systems, the intercom systems,” Gioia says. “They will all work well together.”
While individual features set operators apart from one another, another key factor in specifying and installing an operator is the common factor they all share: standards.
Two major standards affect gate operators. UL325 specifically deals with the manufacture and design of the gate operators themselves, and ASTM F2200 affects the requirements, design and construction of the vehicular gate system.
If a dealer isn’t familiar with both standards, find one who is, Sedivy says. “They will get themselves into trouble if the operator system doesn’t meet the standard requirements.”
Power OptionsAnother key question in choosing a gate operator is what type of power it will have.
“There are operators with AC motors and there are operators with DC motors,” Sedivy says. “DC motors often have a built-in back-up with batteries in the operator that will keep the operator running if you have a power outage. On the other hand, AC motors are typically used on larger gates because they are more powerful. I tend to think of the DC product line as residential and light duty commercial and the AC line can be used across the board.”
DC motors have added features, Gioia says. “DC motors make it easier to add slow start and slow stop on a gate. They also add battery back-up systems so the gate can keep running even if you lose power.”
Experts say that often the choice is obvious.
“What is available? That is the easy way to do it,” Sedivy says. “The typical residential application, you are looking at a 115V AC product. Once you are in the commercial/industrial sector, now you could be looking at anything from 115V to 460V AC. It also depends on how far the wire run is. If I have to pull power from 200 yards away, 115V doesn’t like distance. There is a voltage drop on the line. When I finally get the wire to the other end it is maybe only 90V and that is not enough to run an operator. This is one cause of overheating motors and burned out circuit boards. In general, the bigger the motor, the more power you need.”
Another option that is gaining popularity in certain applications is solar power.
“Traditionally solar applications have come into play when AC power was not available at all,” Luker says. “Now there is a small, but growing percentage going solar. In our market we probably do solar on 10 percent or less of overall applications.”
But new government incentives may be changing that. “There are tax incentives to help people go solar,” Gioia says. “These new incentives cover not only the physical cost of the gate system, but also the total installed cost.”
Installation and Service ConsiderationsOnce you have all the required elements in place, installation becomes key. Hopefully, if the systems have been well designed and chosen to fit the needs of the application, installation should be straightforward.
One of the installation considerations specific to gate operators is the mounting. Generally they are either pad mounted or post mounted.
Similar to the slide versus swing gate decision, sometimes regional weather makes the decision easy. “Here in California everything is typically pad mounted,” says Gary Baker, vice president of marketing for Linear. “But in the Midwest with the snow and water, the dealer doesn’t want to be in the muck so they put posts set in cement and install the operator up off the ground.”
Luker adds: “In the Midwest and Northeast the frost line would require the pad to be so large it would be costly. That is another reason they went to posts. It keeps it out of the snow and rain and everything else.”
This post construction is paramount, Nichols says. “If it isn’t correct, if it is weak, not deep enough or the support post is not correct, you will have a system that fails. Similarly if gate construction is not adequate, if it has too much built-in flex or it’s too long, you can have failures of the gate system.
“The key to a successful swing gate installation is post construction and with a rolling or slide gate, it is gate construction. The gate operator itself is designed to move an object. The bulk of gate operators are designed to do that very well. But the operator is only a piece of equipment that moves something that has been constructed. If it hasn’t been constructed right, the operator is going to have a problem.”
Grant agrees. “It is also important who installs not just the operator, but the fence itself. If the gate is out of line or installed improperly, there can be quite a bit of undo stress on the gate. There will be more frequent repairs to the operator. It’s not the operator’s fault; it is just working against a mechanical problem caused by the gate.”
And that is why no talk about gate operator installation is complete without mentioning service issues.
One of the things an installer or integrator can do to help ensure a good service relationship with the client is to start by choosing a manufacturer with a good training program and good customer support, Nichols says.
“Anyone doing gate operators should look at the equipment, talk to the companies manufacturing it and build a relationship with them. It should be someone with a good tech department. There is nothing like sitting on a job site and being put on hold for 30 minutes.”
Some manufacturers even offer products with microprocessors in them that will send gate operator data back to the controller for troubleshooting, Sedivy says.
“One of the things that people often overlook is establishing a maintenance program at the site,” Gioia says. Making sure the components are in proper working condition and implementing a small maintenance program to make sure the gate is properly oiled, the belts are in good condition and the reversing system is working properly will save a fortune in damage later, he adds.
When You Need More Than a GateFor some installations, an automated gate doesn’t provide the necessary security for the job. Government, utilities, correctional facilities and military installations are a few prime examples of sites that may want a higher security solution in addition to gates and gate operators.
“The gates that gate operators typically open and close give you the benefit of an automated system,” says Kenneth Grant, director of client relations, USR, Franklin, Tenn. “They provide a pretty good deterrent to unauthorized personnel entering a facility. But it’s very rare and expensive to have that gate really provide defense against a vehicle driving right through. As soon as you have that, your weights on the fence and the need to anchor it to the roadway are beyond the capabilities of a gate operator.”
That is where vehicle barriers, such as bollards and wedges come in. These products have been around for some time, but really took off post-9/11. Since that time, some manufacturers have branched out to include new and different approaches to these high security needs.
USR, for example, offers a Department of State and ASTM crash rated vehicle “net” called a Ground Retractable Automobile Barrier (GRAB). “The disadvantage of wedges and bollards is they are very catastrophic and cause severe injury and fatalities,” Grant says. “They are also quite expensive to repair once an incident occurs, and often difficult to even get down so a business can go back to being operational.
“Our flagship product is a set of steel cables that is lifted into position from a recess in the roadway. It’s an all electric system so you don’t have the reliability or maintenance issues you would with hydraulics. But it also absorbs the energy of the impact so the vehicle occupants can walk away unharmed. At the same time there are four pins designed to be the only part of the system that breaks in such an impact. So instead of weeks of construction to get back up and running, a facility only needs 30 minutes and $100.”
Usually the system is used in conjunction with a gate system, going up and down as the gate opens and closes. “A fence gate can take up to 20 seconds to open or close. These take about two seconds,” Grant adds.
All-electric is the twist that RSSI, Panama City, Fla., puts on its crash-rated vehicle barriers.
“Most of our industry is comprised of hydraulic barriers,” says Bill Jempty, vice president of sales and marketing, RSSI. “Our barrier, in contrast, is an electric solution.”
Because of that, the barrier can operate as a true access control product, he adds.
“Electric is faster in normal operation. But also hydraulics don’t operate that well in high duty cycles. They are very high maintenance. Ours are designed for high duty, moving heavy weight at very fast speeds.”
Still, the system often is used in conjunction with other gate operator products, such as an aluminum traffic arm. “It acts as a physical barrier to vehicles that are authorized to come into the site, for safety,” Jempty says.
Sometimes it’s not a vehicle you want to keep out, but a pedestrian on foot.
That is the theory behind Gallagher Security Management Systems, Sanford, Fla.’s Power Fence system.
“Our system is a non-lethal electric fence that we retrofit to existing perimeter fences,” says Thomas LaRose, business development manager for Gallagher.
“We put our fence from the ground to two feet above the existing fence. Wires go every 3 5/8 inches, so in an 8-foot example, we would have 27 wires. We send a DC pulse current out on the fence line, which acts as a physical deterrent and detection at the same time. It sends out the current and looks for the same voltage to come back. If it doesn’t, it alarms.”
The Power Fence attaches right to the gate and gate operators, he says. “When the gates open, our system will temporarily shut off within that zone.”