Frequently Asked Questions Regarding UL 325 7th Edition 2018

UL325 FAQs

Q1: Where can I obtain basic understanding of UL 325 and its history?

A: The Door and Access Systems Manufacturing Association (DASMA) publishes many excellent Technical Data Sheets (TDS). TDS #353 provides details about Underwriters Laboratories (UL), the history of UL 325, and many other key details.

 

Q2: How does UL 325 7th Edition differ from the 6th Edition?

A: Changes were made to the 7th edition to clarify confusion that occurred in 2016, the effective date of the 6th Edition, regarding the minimum number of entrapment protection sensors required to meet the standard. Since 2000, UL 325 has required gate operators to be installed with two independent means of entrapment protection in both directions of gate travel. In 2016, an external sensor monitoring requirement was added that prevents fully automatic operation until the minimum number of entrapment protection sensors have been installed. The wording of the UL 325 7th Edition was clarified to resolve differing interpretations regarding the minimum number of sensors required for each type of gate.

 

Q3: What is the minimum number of external entrapment protection sensors (e.g. photo eyes and/or edge sensors) required in a typical automated gate installation?

A: The correct answer depends on the type of operator, the type of gate and the number of entrapment zones that must be protected. Table 32.2 (below) was added to the UL 325 7th Edition, clarifying the minimum entrapment protection sensor requirement. An inherent sensor is the first method of entrapment protection for most gate operators. The second method of entrapment protection is the external entrapment protection sensor(s) added by the installer.

Table 32.2: Minimum Quantity of Entrapment Protection Methods

	Opening	Closing
Horizontal Slide Gate	2	2
Horizontal Swing Gate	2*	2
Vertical Pivot Gate	2	2
Vertical Lift Gate	1	2
*For a horizontal swing gate operator, at least two independent entrapment protection methods are required in each direction of travel. If an entrapment zone is not present in one direction of travel, only one method of entrapment protection is required in that direction of travel. The reverse direction must have two independent entrapment protection sensors.

 

Q4: What does “monitoring” mean?

A: Monitoring is an electrical method of verifying that an external sensor has been installed. Every external sensor that protects against entrapment must be monitored for presence at least once per gate cycle.

  

Q5: How does an operator monitor an external sensor?

A: Manufacturers use one of three different methods to monitor external sensors:

1. Connecting sensors using a Normally Closed (N.C.) circuit and cycling the power
2. Detecting a frequency or pulse generated by the sensor (2- or 4-wire design)
3. Detecting a resistor, which enables a small current to pass through the circuit

 Nice branded operators utilize different methods of monitoring depending on which external sensors are used. 936 and 1050 Control Boards are equipped with BlueBUS, a proprietary communication protocol, which enables a simple two wire interface to be used that monitors multiple sensors. BlueBUS is used to connect the photo eye(s) included with each operator. Additionally, the 936 and 1050 are capable of monitoring a 300Hz pulse signal. The operator manual provides information about this setting.  

 HySecurity Smart Touch and SmartDC control boards use the N.C. method to monitor external sensors  The Nice | HySecurity SmartCNX uses both resistive and pulse monitoring, and automatically senses which type is used. SmartCNX also uses Nice BlueBUS technology for monitored sensors.

 

Q6: How many monitored external sensors can be connected to Nice | HySecurity operators?

A: Nice branded 936 and 1050 control boards can monitor up to six sets of sensors, when using BlueBUS, which can be connected in a daisy-chain. Jumpers on the sensors must be set to indicate what function the sensor performs. The 300Hz pulse inputs can accommodate two sensors total, one per input.

HySecurity Smart Touch and SmartDC control boards have three programmable external entrapment sensor inputs and are marked: Sensor 1, Sensor 2, and Sensor 3. Only one sensor can be connected to each input, for a maximum of three external sensors. If more external sensors are required, the “The Solution” (part number MIM-62), a Miller Edge adapter, can be added. The Solution module has six inputs and two outputs, which must be wired to two of the three sensor inputs on the control board. With The Solution module, a maximum of seven external sensors can be used.

The Nice | HySecurity SmartCNX controller has inputs for 5 entrapment sensors in addition to the BlueBUS for up to 11 entrapment sensors. 6 Addition sensor inputs are available with the SmartCNX I/O Expansion module.

 

Q7: How is it possible to monitor an Edge Sensor since it is a Normally Open contact?

A1: Newer Edge Sensors have an internal resistor and this resistor allows a small current to pass through, which enables monitoring. Older Edge Sensors without a 10k resistor cannot be monitored, therefore it is important use Edge Sensors with a 10k resistor.

A2: For hard wired edges, the method of monitoring will vary by brand and control board.

• Nice 936 and 1050 Control Boards must be used with a converter to convert the resistive input to a pulsed output. The Miller Edge “GEM-103” is available for this purpose.
• HySecurity Smart Touch and SmartDC control boards require an Edge Interface Module: the HySecurity Hy2NC (part number MX4018). This module monitors the 10k ohm resistor in the Edge Sensor and converts the contact from Normally Open to Normally Closed. The Hy2NC module has two channels and can support up to two hard wired Edge Sensors when connected to two of the three Sensor inputs on a HySecurity control board.
• The Nice | HySecurity SmartCNX controller uses resistive monitoring and requires no adapter for edge sensors.

A3: If the Edge Sensor is transmitted wirelessly to the gate operator (not recommended), a Wireless Link Kit is required.

• Nice 936 and 1050 control boards have been tested and are compatible with the EMX WEL-200
• HySecurity Smart Touch and SmartDC  and Nice | HySecurity SmartCNX control boards are recommended for use with the EMX WEL-200 or the iGAZE RE Kit

 Wirelessly transmitting two Edge Sensors, such as the leading- and trailing-end of a slide gate, will require two transmitters. Only one receiver is needed, however, because the receiver has multiple channels. Each channel can monitor one transmitter.

 Note: wireless edge transmitters are prone to Radio Frequency Interference (RFI) issues. Avoid using wireless edge transmitters in RF locations that are crowded, such as police or fire stations, courthouses, airports, and defense/military bases.

 

Q8: Why does Nice | HySecurity recommend hard wiring an Edge Sensor rather than a wireless edge transmitter?

A:

1. Hard wiring an Edge Sensor reduces risk of RFI interference, which may cause monitoring faults
2. Hard wired Edge Sensors offer faster signal communication, enabling faster reversal
3. Wireless transmitters require batteries, which can fail
4. Hard wiring an edge sensor is more cost effective

 

Q9: Is installing Edges Sensors on the leading and trailing end of a sliding gate the best way to protect against entrapment?

A: Not necessarily. While the leading and trailing ends of a sliding gate are potential entrapment zones, the risk of entrapment, serious injury or death is greatest at the “Draw-In” zone. Common installer practice has been to prioritize installation of edge sensors on the ends of a sliding gate, while not protecting the “Draw-In” zone where the gate travels past a rigid object such as a wall, gate support posts, or stationary fences. Nice | HySecurity strongly recommends installing the first Edge Sensor to protect the Draw-In zone. See slide gate illustration below:

 

 

Q10: What happens if one of the external entrapment protection sensors becomes disconnected or fails in a Nice | HySecurity gate operator?

A: The gate operator monitors the “presence” of each entrapment protection sensor. When the operator no longer detects a sensor, it will cease automatic operation in the direction of the missing or failed sensor. The operator will still function, but only with a “Constant Hold Input” from a wired access control device within sight of the gate. .

 

Q11: Can any UL or ETL listed sensor be installed with any UL or ETL listed gate operator?

A: No. In addition to UL 325 component recognition or an ETL listing, a sensor must also be tested with the specific gate operator to meet the UL 325 Standard of Safety and be included on the operator manufacturers list of compatible sensors (60.8.7).

 About Component Recognition:

The gate operator manual must be consulted to determine components that are tested for use with that specific gate operator. All entrapment protection sensors, such as photo eyes and edge sensors, must be tested by UL, ETL, or another Independent Test Laboratory. Successfully passing a UL 325 component test allows the component manufacturer to “Mark” the product with a label that looks like one of these:

 Note: each sensor, brand, and model, must still pass a manufacturer test proving its compatibility and functionality when connected to a UL 325 or ETL listed gate operator. All gate operator manufacturer’s installation instructions must list the sensors which are approved for connection to their gate operators (32.2.1.1, 60.8.7).

 

Q13: Does Nice | HySecurity recommend a specific brand of edge sensor?

A: Refer to the Nice | HySecurity recommended sensor list for sensors that have been tested with and are recommended for use with both Nice and HySecurity branded operators. However, ASO brand Edge Sensors have a robust design and are less prone to monitoring failure than edge sensors made with rubber coated foam.

For swing gates, Nice | HySecurity recommends using a “wraparound” style edge sensor on the leading edge of gates with a . A single wraparound sensor can protect in both directions of travel (open/close). All HySecurity branded Smart Touch Controllers have an input option that enables a single wraparound Edge Sensor to reverse the gate when opening or closing.

 

Q14: What other key changes were made to the 7th Edition UL 325, effective 8/1/2018?

A: Several other noteworthy clarifications and additions are outlined below:

1. Entrapment zones are now defined for each type of gate and operator instruction manuals are the best source for this information (4.23, 4.24, 4.29, 4.34)
2. An important clarification stated that every external entrapment protection sensor installed must be monitored (32.1.8)
3. Common work around techniques to bypass monitoring have been specifically prohibited:
   1. It shall not be possible to make simple modifications in the field by adding, suppressing, or changing, either on the operator or external entrapment protection device(s), to bypass, interfere with, or otherwise defeat the monitoring function, via:
      1. The connection of wires;
      2. Terminals;
      3. Switches;
      4. Jumpers;
      5. Components supplied with the operator or external entrapment protection device (32.1.10)
4. The manual shall not provide instructions for which the stated purpose is to reprogram, reconfigure, or reset the monitored outputs such that they do not comply with the minimum entrapment protection requirements, except to revert to original factory settings. (32.1.11)
5. The operator shall not be provided with resistors installed or intended for installation across the terminals that are intended for monitored external entrapment protection devices and the manufacturer shall not recommend the use or installation of such resistors (32.1.12)
6. A component, such as a resistor, capacitor, etc. required for monitoring shall be permanently installed at the factory by the manufacturer of the entrapment protection device (32.1.13)
7. UL 325 7th Edition is now the national standard in Canada for Door & Gate Operators

 

Q15: If older Nice | HySecurity controllers or control boards require replacement, does the operator require new installation to comply with the UL 325 2018 standard?

A: No. The requirements of the UL Standard are not retroactive to older operators. System updates and the addition of monitored safety devices is recommended for Nice branded 936 and 1050 Control Boards. HySecurity branded Smart Touch Controllers and software manufactured in 2018 is backwards compatible with older operators.

 

 Q16: Do gate operators manufactured prior to August 1st, 2018 require monitored entrapment protection sensors?

 A: Monitoring of external entrapment protection sensors is only required for automatic gate operators manufactured after January 11, 2016. There is no requirement to update pre-2016 operators to comply with a newer standard.

  

Q17: Can I update an older Nice | HySecurity operator to meet the 2018 UL 325 standard?

A: Yes! The Nice 936 Control Board can be reflashed in the field with the most current version of firmware. The 1050 Control Board cannot be reflashed in the field; however, some distributors have the ability to reflash the board with current firmware, but it may require replacement. HySecurity branded controllers can be updated by uploading new software: version h4.60 (Smart Touch) or h5.60 (Smart DC) or later. Tested and approved entrapment protection sensors must be added.

 

Q18: What can be done to assure more reliable photo eye performance?

A: There are a number of factors that can affect the maximum range and/or performance of photo eyes. It is important to use photo eyes within the range specified by their manufacturer. Using a photo eye beyond its rated range can be unreliable in adverse weather. Additionally We recommend the use of hoods or preferably covers over photo eyes and reflectors to shield all the optics from dirt, condensation and ice. Photo eyes approved for use with Nice | HySecurity operators are outlined in tables above, along with a conservative range estimate based on tests and/or a detailed review of the specifications.

 

Q19: Can a new edge sensor (with a resistor) be added to an older gate operator without a monitoring circuit? 

A: No. For 2015 and older Nice and HySecurity branded gate operators, either non-monitored edge sensors must be used, or the firmware must be updated and set to use 2018 monitoring standards.

 

Q20: What devices have been tested for use with Nice | HySecurity gate operators?

A: Refer to the Nice | HySecurity recommended sensor list for sensors that have been tested with and are recommended for use with both Nice and HySecurity branded operators. These sensors are certified to comply with UL 325 7^th Edition. This information is also available in each operator manual.