UL 325 is the safety standard for gate operators. It requires at least two independent entrapment protection means for each entrapment zone, such as photo eyes, edge sensors or the operator's own sensing. External sensors must be monitored, and a gate must begin reversing within 2 seconds of sensing an obstruction. Never bypass a sensor.
What UL 325 is
UL 325 is the Standard for Door, Drapery, Gate, Louver, and Window Operators and Systems. DASMA says its first edition came out in 1973 and covered garage door operators, and that gate operator makers pushed to add vehicular gate rules in the early 1990s.
A product is not approved by UL. It is tested by a laboratory and, if it meets the standard, listed and labeled. Labs other than UL do this too, so look for the mark of a recognized listing agency on the operator. For a house, the usage class is Class I, defined as a gate operator for garages or parking areas of a residence of one to four single families.
What entrapment protection means
The standard defines entrapment as a person being caught or held in a position that increases the risk of injury. A gate can pin someone against a post, a wall or the fence. Entrapment protection is anything that senses that and stops or reverses the gate. The standard names these types:
- Type A: inherent protection, built into the operator, such as sensing the load or motor current
- Type B1: a non-contact sensor, usually a photo eye
- Type B2: a contact sensor, such as an edge sensor along the gate
- Type C: inherent force limiting, such as an adjustable clutch or pressure relief
- Type D: a control that works only while you hold it down
How many sensors does a gate need?
DASMA quotes the standard: an operator must have provisions for, or be supplied with, a minimum of two independent entrapment protection means for each entrapment zone, and it must operate only after those means are installed and enabled. The same type of device cannot serve as both. For a sliding gate that means two in each direction. A swing gate needs two in each direction too, except that a direction with no entrapment zone needs only one.
That is why a single photo eye on a gate is not the whole answer. The second layer is often the operator's own sensing or an edge sensor.
What the sensors must do
External sensors must be monitored. The operator checks that each one is present and working during every open and close cycle. DASMA's brochure says that since January 2016 a fault means the gate operator will not run, unless a hold-to-run control is being used. So a knocked or dirty photo eye can stop a gate, and that is the system working as designed.
After an obstruction is sensed, reversing must begin within 2 seconds, and after the first contact the gate must reverse at least 2 inches. DASMA's checklist describes testing this on a closing gate with a solid object, which is a test for your installer or technician to run, not one to improvise.
Taping over a photo eye, wiring around an edge sensor or turning off sensing to get a stubborn gate to close removes the protection the standard requires. Find out why the sensor is faulting: usually dirt, a bumped bracket, a damaged wire or a failing device. See why an electric gate will not close.
Why this matters at home
DASMA lists the situations behind most gate injuries: reaching through a gate to work the controls, climbing under or through the gate path, children playing near it, and untrained people adjusting a gate. Its guidance is to put controls at least 6 feet from the gate, to provide separate pedestrian access, and to display at least two warning signs where they can be seen from both sides.
DASMA's checklist also warns that operators made before March 2000 may lack adequate safety provisions and that replacing them is the preferred option. If that sounds like your gate, read repair or replace a gate opener.
Have your gate checked
Emil Garage Doors repairs gates, sensors and operators for Southern California homes, for example in Rancho Mirage, La Puente and Anaheim. See electric gate repair, then call (213) 340-4232 or send the estimate form with the operator brand, and tell us what the sensor lights are doing. We confirm the price after we see the gate.
Questions people ask
What is UL 325 for gates?
It is the safety standard for gate operators, among other operators. It sets rules for entrapment protection, monitoring of external sensors, reversing, warning signs and instructions.
How many safety sensors does my gate need?
At least two independent entrapment protection means for each entrapment zone, according to DASMA's summary of UL 325. They must be different types, and external ones must be monitored.
Why does my gate stop when the photo eye is dirty or misaligned?
External sensors are monitored. If the operator cannot verify one, it will not run. Clean the lens and check the alignment, then call a technician if the fault stays.
Can I bypass a gate sensor?
No. It removes protection the standard requires and can lead to serious injury. Have the cause of the fault found and fixed.
More guides
Sources
- DASMA Technical Data Sheet 353: Vehicular Gate Operators and the ANSI/CAN/UL 325 Standard
- DASMA Technical Data Sheet 352: Automatic Vehicular Gate Operating Systems, Guidelines for Specifiers, Designers, Dealers, Installers and End Users
- DASMA: Gate System Safety brochure (be safe, be aware, installation and maintenance)
- DASMA Technical Data Sheet 371: Automated Vehicular Gate Systems, Checklist for Inspectors and Property Owners