Monthly Archives: December 2015

Internally Speaking: Applications Using the EVS-INT50W

I wrote a blog in May 2015 introducing our new EVS-INT50W internal amplifier. An overview of the product was provided along with a brief mention of applications. In this installment, I would like to discuss a few specific applications: Day Care Centers, Assembly Occupancies, K – 12 Educational Facilities, and Lodging.

evs-int50w-diagram1Day Care Centers is an ideal application for the internal amplifier because of limited wall space for mounting external hardware and the requirement for the 520Hz low frequency output. Many jurisdictions are adopting the 2012 edition of the International Building Code (IBC) which states that a manual fire alarm system that initiates the occupant notification signal utilizing an emergency voice/alarm communication system shall be installed in Group E occupancies.  Day Care facilities fall under a Group E occupancy. In addition, Section 18 of the 2013 edition of NFPA 72 states that effective January 1st, 2014, audible appliances provided for the sleeping areas to awaken occupants shall produce a low frequency alarm signal.

As defined by NFPA 101, an Assembly Occupancy is an occupancy used for a gathering of 50 or more persons for deliberation, worship, entertainment, eating, drinking, amusement, awaiting transportation, or similar uses. A common example of an assembly occupancy is a place of worship where the area of congregation will require voice evacuation. The EVS-INT50W is perfect for this application because vital wall space is saved while providing a 50 watt single speaker circuit amplifier that meets required decibel output and audibility requirements

K – 12 Educational Facilities offer the ability to use the internal amplifier with the flexibility of integrating distributed amplifiers. As with the Day Care Center application, K through 12 educational facilities fall under a Group E occupancy. Since many classrooms and other gathering locations will have an occupant load of greater than 30 people, these facilities are prime candidates for voice evacuation and emergency communications. The 5820XL-EVS and the EVS-INT50W will cover an area or areas of the facility while distributed amplifiers will cover other areas of the facility. This is quickly becoming a popular method of distributing voice.

evs-int50w-diagram2Due to recent code updates and state/local legislation, low frequency is becoming common in the lodging industry. Section 18 of the 2013 edition of NFPA 72 states that effective January 1st, 2014, audible appliances provided for the sleeping areas to awaken occupants shall produce a low frequency alarm signal. Full coverage for low frequency voice evacuation can be accomplished by using a combination of the internal amplifiers and the distributed EVS-100W amplifiers. As with the K – 12 Educational Facilities application, the 5820XL-EVS and the EVS-INT50W will cover an area or areas of the lodging facility while the distributed EVS-100W will cover other areas of the facility.

Do you have applications where the EVS-INT50W would be helpful? Please let us know by clicking on the Leave a Reply link above to enter your request.  Click here to download the EVS-INT50W data sheet.


About the Author
Mark Indgjer is a Product Marketing Manager with Silent Knight.  Mark joined Silent Knight in 1988 and is responsible for new product development, product marketing and much more.  Mark is also NICET Level II certified.​

New NICET Certification Program

Through the efforts of the Automatic Fire Alarm Association (AFAA), the National Institute for Certification in Engineering Technologies (NICET) is now offering a new certification program for Inspection and Testing of Fire Alarm Systems. This new certification program consists of two levels.

  1. Level 1 is for those who test “Basic” fire alarm systems, with a minimal amount of interconnection with other systems. 6 months of I&T experience is required. Individuals already certified for Fire Alarm Systems at Level 2 are considered to meet the testing requirement for Inspection and Testing Level 1.
  2. Level 2 is for those who test “Complex” fire alarm systems, including systems with multiple or complex interconnection with other systems. 18 months of I&T experience is required. Individuals already certified Fire Alarm Systems Levels 3 or 4 are considered to meeting the testing requirements for both Inspection and Testing Level 1 and Inspection and Testing Level 2.

This new certification is not meant to replace the existing Fire Alarm Systems certification, but is intended to start having certifications more specific to an individual’s work experience. The intent is to broaden the base of certificate holders in the fire alarm industry. AFAA promoted this to continue our efforts to improve professionalism as well as improve the quality of inspection and testing of fire alarm systems.

For more information, go to There is a link to this certification on the home page. For more information on AFAA’s new Inspection and Testing Seminar to help prepare for these tests, look at the Training Calendar under the Training tab on


About the Author
Tom Hammerberg is Technical Director of the Automatic Fire Alarm Association. He has been in the alarm industry for 40 years and with AFAA for 21 years, serving as President/Executive Director from 2003-2014. Tom is NICET Level 4 certified in the field of Fire Alarm Systems and is a Certified Fire Protection Specialist. Tom represents AFAA on NFPA 3 and 4, the NFPA 72 Technical Correlating and Protected Premises Technical Committees, NFPA 90A and NFPA 101/5000 Building Services and Fire Protection Equipment and Fundamentals Technical Committees, the ICC Industry Advisory Committee, Life Safety Section of the International Association of Fire Chiefs and the Codes, Standards & Technical Research Committee of the Center for Campus Fire Safety.

Why Training is a Must in the Fire Alarm Industry

As a trainer for Silent Knight, I know how important training is in this business. I also appreciate how essential it is to keep pace with product updates, product releases, and trends in the fire alarm and life safety industry.

Our responsibility is to ensure that people who attend Silent Knight training classes receive the best learning experience as possible. Our training department works closely with Engineering and Product Management to guarantee that our training modules and product demonstration equipment are current. We check equipment after each training session to confirm everything is in working order, and we also communicate with each other to find out what went well and how the experience could improve.

fire-alarm-industry-trainingA key function of a trainer in the fire alarm business is to follow the industry. Training classes are Silent Knight product-specific, but topics such as code, industry products, and trends are prevalent throughout our sessions to provide well-rounded classes. Over the years it has been proven that one of the best resources for industry information is you, the class participant. There is a wealth of knowledge and experience in every training session we conduct, which is why you will find substantial class participation. This is what takes our training to the next level. In fact, it is not uncommon for a trainer/trainee working relationship to form beyond the training class.

Product training is critical in our line of business because the ultimate goal is life safety. Preparing and offering training is a responsibility we take seriously because understanding code and requirements, using the right equipment, and knowing how to install it ensures optimal solutions to save lives.

Let us know your thoughts on training by clicking on the Leave a Reply link above to enter your request. Click here to visit the Silent Knight training page.


About the Author
Brian Brownell joined Silent Knight as a Technical Trainer in 2011 and has worked within the fire alarm industry for 30 years.​

Tech Tip: EVS-INT50W Power Wiring

The EVS-INT50W is an amplifier that offers a single speaker circuit capable of supporting up to 50 watts of power and is compatible with version 15 of the 5820XL-EVS. Although it is similar to the distributed 50, 100, and 125 watt amplifiers, there are subtle differences.

One of the first things you will notice is that the EVS-INT50W does not come with an enclosure. The reason for this — and why it is described as an internal amplifier — is that it mounts in the 5820XL-EVS cabinet. No external cabinet or hardware is required: this provides the benefit of saving valuable wall space as well as installation time and money.

The other difference you will see is that there is no primary AC and battery backup. The EVS-INT50W is powered by the 5820XL-EVS panel. This is where it can get tricky. To power this amplifier, one of the 6 Flexput™ circuits on the 5820XL-EVS will be programmed for Constant Auxiliary Power and run to the power input on the EVS-INT50W. The SBUS connection, which is normally 4 conductors, will be 2 conductors for the A and B data connections. Do not use the SBUS power (- and +) to power the amplifier. The amplifier draws close to 3 amps in full load. SBUS power only supplies up to 1 amp. Be sure to account for the power draw in your 5820XL-EVS battery calculations.


The internal amplifier is an addressable device, so be sure to set the dipswitches on the unit before powering it up. Also ensure that the panel is programmed to look for the address you set on the amplifier. After this, all options are programmable, such as mapping the speaker output for proper activation, 25 or 70.7 Vrms operation, Class A or Class B speaker wiring, and 520 Hz low frequency output.

Have you installed the EVS-INT50W? Please let us know your experience by clicking on the Leave a Reply link above to enter your request. Click here to visit the EVS-INT50W web page.


About the Author
Bill Root is the Technical Support Supervisor for Silent Knight. Bill joined Silent Knight in 1988 and is responsible for managing applications and technical support across the Silent Knight product line. Bill is also NICET Level II certified.

Catch the Drift: An Overview of Detector Drift Compensation

Addressable fire alarm control panels provide several enhanced features that are not provided with conventional fire alarm control panels. Several of these features relate specifically to the addressable detectors, such as Drift Compensation, Maintenance Alert, and Calibrated Sensitivity testing. In this installment, we will provide an overview of Drift Compensation.

Let’s look at an addressable detector on a Silent Knight addressable fire alarm control panel. When a detector is installed and programmed, it communicates with the fire alarm control panel to determine a variety of thresholds. These thresholds determine events like trouble and alarm conditions. Once the detector reaches a specific threshold, the trouble or alarm condition would occur. Over time, detectors will accumulate contaminates such as dust, which can cause the sensitivity of the detector to change. In order to keep the sensitivity constant, the detectors adjust their internal thresholds to compensate for these contaminates. This process of adjustment is called Drift Compensation and ensures that detectors have the same sensitivity as when they were first taken out of the box.

detector values - drift compensation

Eventually, detectors will reach a point where they will not be able to compensate for contaminates. When this occurs, a Calibration Trouble will annunciate for the detector or detectors in question. It is important to note that addressable detector chambers can be cleaned. A new detector is not required when it reaches its Calibration threshold. When a clean detector is reinstalled, the panel and detector will communicate to reestablish thresholds and the Calibration Trouble will restore. Aside from keeping a constant sensitivity over time, a key benefit of Drift Compensation is that it dramatically decreases the amount of service calls as the time between cleanings increases.

Did you know the Detector Status upload with SKSS software is a U.L. listed Calibrated Sensitivity Smoke test? Please leave a comment by clicking on the Leave a Reply link above to enter your request.


About the Author
Jack Grones is an Application Engineer with Silent Knight and holds a NICET Level III certification.  Jack joined Silent Knight in 1978 and is responsible for applications and technical support.