Tag Archives: EVS-INT50W

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.​

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.

How To: Installing the Internal Amp (EVS-INT50W)

We are excited about a new product release for the 5820XL-EVS family.  The EVS-INT50W is a 50 watt, single speaker circuit amplifier.  What makes this amplifier unique is its ability to be mounted and housed in the 5820XL-EVS cabinet.  This new amplifier mounts on the standoffs where 5815XL point expanders are normally mounted, thus saving valuable wall space.Internal Amp install

The EVS-INT50W requires a total of 3 pairs of wires for installation: 2 for the 24 VDC power, 2 for the SBUS data and 2 for the VBUS.

  • 24 VDC constant power can be obtained from any of the 6 Flexput™ circuits programmed as constant auxiliary power. Eliminating an additional AC circuit and backup batteries to power the amplifier saves time and money.
  • The EVS-INT50W is an intelligent device requiring SBUS wiring to the 5820XL board assembly. The A and B terminals on the amplifier will wire to the SBUS Out A and B terminals on the 5820XL.
  • The amplifier requires a VBUS (Voice BUS) connection to the VCM (Voice Command Module) located on the dead front door of the 5820XL-EVS cabinet. The VBUS carries the recorded voice messages and microphone to the amplifier.  The 2 wire VBUS runs from the VBUS out on the VCM to the VBUS terminals on the amplifier.  Since the VBUS is an audio circuit, shielded wire is recommended.
  • Using shielded wire, connect the speaker circuit to the Speaker Out terminals on the amplifier. The speaker circuit requires a 15K end of line resistor.  There is an option to wire the speaker circuit as Class A.  In this case, an end of line resistor is not required and the shielded pair would return to the Speaker In terminals on the amplifier from the last device on the circuit.

Before applying power, use the dipswitches on the EVS-INT50W to set the address.  You will then need to program the EVS-INT50W into the 5820XL-EVS, by following these steps:

  • Open your program file in SKSS and click on the “System” tab. Under “Module”, right mouse click and select “Add”.  The “Add Module” window will appear and you will scroll down to highlight the EVS-INT50W voice amplifier.  Select “OK” and ensure that the ID of the module matches the ID set with the dipswitches.
  • Select the “Output Groups” tab. Scroll down to Module 34 and right click on the Type box across from Flexput™ circuit you want to use for constant auxiliary power.  Select the “Aux. Power” bullet and ensure that “Constant” is selected in the drop down.  Save the configuration and download to the panel.

You have successfully installed the EVS-INT50W internal amplifier!

The EVS-INT50W works with version 15 of the 5820XL-EVS and version 3.64 of SKSS.  Download SKSS for free and check out our new EVS-INT50W video at www.silentknight.com.

You can also click the link to download the EVS-INT50W sell sheet.

About the Author
Brian Brownell joined Honeywell in 2011 and brings 30 years of fire alarm industry expertise to his current role as a Technical Trainer for Silent Knight. ​