Automated Safety

Class I – Residential Vehicular Gate Operator

A vehicular gate operator system intended for use in a single-family dwelling or related parking garage or parking area.

Class II – Commercial/General Access Vehicular Gate Operator

A vehicular gate operator system intended for use in a commercial application that includes multi-family housing, hotel, garages, retail store, or other building servicing the general public.

Class III – Industrial/Limited Access Vehicular Gate Operator

A vehicular gate operator system intended for an industrial application or building, manufacturing, loading dock area or other locations not intended for the general public.

Class IV – Restricted Access Vehicular Gate Operator

A vehicular gate operator system intended for a guarded industrial operation, correctional facility, airport or other restricted access not servicing the public. Unauthorized access is prevented and the operation is under direct supervision by security personnel.

UL 325 Standard

A key part of the UL 325 standard is a table that summarizes the entrapment device options for different classes of operators of the various types of gates included in the standard. Refer to this table as you read about the provisions that are described in the following sections.

Gate Definition and Types

UL 325 defines a gate as “a moving barrier such as a swinging, sliding, raising, lowering, rolling, or the like, barrier that is a stand-alone passage barrier or is that portion of a wall or fence system that controls entrance and/or egress by persons or vehicles and completes the perimeter of a defined area.” The main types of gate operators/systems addressed in UL 325 are barrier, vertical pivot gate, horizontal slide gate, swing gate and vertical slide gate. It is important to note that all gates included in UL 325 are defined as vehicular gates and NOT PEDESTRIAN GATES. Property owners are expected to provide a separate entrance for pedestrian access.

UL 325 defines the allowable entrapment protection options for each class as follows:

1. Each class must have primary and secondary entrapment provisions;
2. Each class must have different types of protection for the different classes of operators as well as for the different categories of operators; and
3. The same type of device cannot be used for both primary and secondary protection.

An exception to compliance with the provisions of the above table has also been noted in the standard. An operator considered exempt would require all of the following:

1. Operates a vehicular barrier (arm) that is not intended to move toward a rigid object closer than 2 feet;
2. Does not have a pinch point between moving parts by virtue of the operator’s design or complying installation; and
3. Is not required to be provided with means to protect against entrapment

Provisions of Note Regarding Gate Operators

We have identified the following notable provisions included in UL 325 that affect gate operators and related safety devices.

1. Class I and Class II operators must have an audio alarm which shall function if 2 sequential activations of the entrapment protection device occur. The “2 sequential activations” is noteworthy in that it is hoped that “nuisance” alarms will be kept to a minimum while still enhancing safe operation.
2. Class I and Class II slide gate operators shall not exceed a speed of 1 foot per second when the operator is pulling 75 pounds or more. Since both classes listed involve general public usage, this maximum established speed strikes a balance between any perceived security issue (a person immediately following the party controlling the gate) and any danger from a person being struck by a gate.
3. A Type B1 or B2 device serving as a Primary Safety Device shall be monitored for the presence and correct operation of the device, including the wiring to it, at least once during each open and close cycle. This requirement is included because these types of safety devices are often used as backup safety devices.
4. Manufacturers will be required to specify a brand and model number of external sensors compatible for connection to an operator. This provision arose from concern over the gate operator external devices acting in tandem as a system, with a fault rate of 6 failures in 1 million hours of use (which equates to 115 years of continuous operation).
5. After sensing an obstruction, reversing must begin within 2 seconds. This requirement is intended to keep a person from being entrapped in a stationary position by the gate system. After the first contact the gate must reverse and travel a minimum of 2 inches. If there is a second contact, the gate must stop, and requires a wired device to reset the operator.
6. After any obstruction reversal by either an A or B2 device, the timer-to-close is disabled until reset. Both A and B2 devices sense direct gate contact with an obstruction, and the devices must perform their intended function without interference from a timer-to-close action.
7. Stop the gate upon sensing a second sequential obstruction, and then not operate until an intended hard wired input is received in most situations, depending upon the combination of types of primary and secondary entrapment protection devices that are used.. A person within the line of sight of the gate must see what has caused the second sequential obstruction and must resolve this obstruction before operating the gate.
8.  If a Type C device is chosen, swing gates must not exert more than 40 pounds of force after initial start-up. The reasoning here is similar to the reasoning given for the speed limitation for horizontal slide gates.

Effect on Installations

The new provisions will have several effects on gate and fence dealers:

1. Gate and fence dealers should look for an indication of the Class of each operator, which will be specified by the gate operator manufacturer.
2. Fence dealer sales personnel must match the site application with the Class of operator. The gate operator manufacturer should be contacted if there is any question about the site application.
3. Both primary and secondary safety devices must be provided and matched to both the operator and site conditions. Although the gate operator manufacturer will either provide or specify these devices, the gate/fence dealer should insure that they are installed and correctly matched. Any questions should again be directed to the gate operator manufacturer.
4. Warning signs must be permanently affixed to the gate panel. UL 325 includes specific requirements on the format, content, and placement of these signs.

Factors Related to Gate Construction and Installation

• Vehicular gate operators should ONLY be used on vehicular gates and never pedestrian gates.
• Adequate clearance should be provided between a swinging gate and adjacent structures to reduce risk of entrapment.
• A sliding gate should work smoothly with easy rolling/movement in both directions, prior to the installation of the operator.
• Controls should be as far away from the gate as possible, at least 6 feet from the gate, to prevent “reach-through” occurrences.
• Warning signs and placards must be installed and be visible in the area of the gate.
• See DASMA TDS-370 for information about gate construction and ASTM F2200, Standard Specification for Automated Vehicular Gate Construction.

Device-Specific Installation Instructions

There are also specific installation requirements for certain types of entrapment protection devices. These specific requirements emphasize the care and attention that each device must be given prior to and during installation.

For gate operators utilizing non-contact sensor devices (Type B1), instructions should be consulted for placement for each application, care should be exercised to reduce the risk of nuisance tripping, and one or more of these devices must be installed where the risk of entrapment or obstruction exists.

For gate operators utilizing contact sensor devices (Type B2), several requirements are spelled out in UL 325.

One or more contact sensors shall be located at the leading edge, the trailing edge, and also post mounted both inside and outside of, a vehicular horizontal slide gate; at the bottom edge of a vehicular vertical slide gate; and at the entrapment point of a vehicular vertical pivot gate.

A wired contact sensor shall be located, and its wiring arranged, so that communication between sensor and gate operator is not subjected to mechanical damage. A wireless contact sensor shall be located where the transmission of the signals is not obstructed or impeded by building structures, natural landscaping or similar obstructions, and shall function under the intended end use conditions.

For gate operators utilizing a continuous pressure activating device (Type D), controls must be placed so that user has full view of the gate area when the gate is moving. A placard must be placed adjacent to the controls and no other activation device shall be connected. Most importantly, an automatic closing device shall not be employed.

Statements in Manufacturer’s Instructions Concerning Installation

Gate and fence dealers can expect to see in gate operator instructions the following statements:

1. The operator must be appropriate for the construction of the gate and the usage class of the gate. The appropriate primary and secondary safety devices to be used are a major consideration to support this requirement.
2. All openings of a horizontal slide gate, and the portion of the fence where the slide gate passes, must be guarded or screened. These specific requirements in UL 325 that govern this provision were developed to address “reach-through” occurrences. For example, slide gates must have a protective cover 48 inches in height extending from the bottom of the gate/fence panel.
3. All exposed entrapment points must be eliminated or guarded. It is up to individual gate and fence dealers to identify these points on a product-by-product basis, or on a job-by-job basis.
4. Guarding must be supplied for exposed rollers. Exposed rollers are regarded as potential pinch points