Q. What is eLYTE isolation equipment?

A. eLYTE isolation equipment is specially designed telephone interface that provides physical separation between the incoming exchange cables and the local telephone circuits.

Q. Why would I need isolation equipment?

A. Normally no isolation is generally required, but for high energy users or electricity generators, substations, or lightning prone locations it is essential to isolate the incoming exchange copper lines from the surrounding environment.

During fault conditions or heavy equipment use, the earth between the customer and the local telephone exchange can vary greatly. 100s’, 1000s’ or in extreme circumstances 10000s’ of volts are potentially presented across copper telecommunication cables.

Q. Why do we need to disable all telephone circuits when working on exchange card enclosure?

A. DAVAS has taken the opinion that any incoming hazardous lines must be isolated from the work environment. Isolating just the circuit being worked on is redundant as adjacent circuits are still terminated to the hazardous circuits.

Q. How far should the Customer enclosure be from the exchange?

A. The Customer cards can be up to 20 meters from the exchange enclosure if utilizing plastic fiber. But due to the design of the equipment, can be as close as 200mm between exchange and Customer enclosures.

Utilising the Multi-Mode Glass fiber eLYTE version can provide up to 1500m of fiber distance depending on loop distance.

Q. What if We only required one or two circuits?

A. The overall enclosure may still be required.
It is recommended to keep the Exchange enclosure as it contains the vital isolation switch.
Customer power can still be provided by the D906-C01 Power Supply Unit.

Customer circuits can be installed in the Customer enclosure which is recommended. And only the breakers required for the number of circuit may need to be installed.

A single card enclosure for DIN rail mounting is also available. Predominately used for the Customer and SMA cards.

Q. How do I now how much plastic fiber I will need?

A. If the length between Exchange and Customer enclosures is straight, then a simple point to point measurement between adjacent enclosure faces is required, DAVAS will add the required length to provide internal distribution.
If the fiber path is more complex a length corresponding to the path the fiber is expected to follow should be measured. Minimum bend radius of 50mm should be adhered too. -Excess cable can be coiled.

Q. Can We install both plastic and glass fiber cards within the same enclosures?

A. Yes. Trunking can be installed to separate the local Plastic circuits from the longer haul glass fiber termination enclosure.

Exchange Terminal Card

Q. What interfaces are provided with the Exchange card?

A. The Exchange card provides an RJ-12 socket for Line termination and two fiber connectors for the Transmit and Receive fibers.

Q. What accessories are provided with additional cards?

A. The Exchange card will be provided with a RJ12 patch cable.

Q. What power requirements are required for the Exchange Card?

A. NONE! The eLYTE Exchange card is line powered from the telephone exchange.

Q. What earthing is provided for the Exchange cards?

A. NONE! The eLYTE Exchange card is designed to be isolated from any earth paths. Any protection schemes that provide a path to Earth must be terminated to the line at a demarcation point outside the EPR area.

Customer Terminal Card

Q. What interfaces are provided with the Customer card?

A. The Customer card provides an RJ-12 socket for Line termination and two fiber connectors for the Transmit and Receive fibers. A plug-gable Screw terminal is provided for DC supply, Wire size 0.5 – 2.5mm2 / AWG 24-12.

Q. What accessories are provided with additional cards?

A. The Customer card will be provided with an RJ12 patch cable.

Each Customer card will require a DC breaker to be installed within a Customer enclosure.
Alternatively the Customer cards could be installed within a smaller single circuit enclosures, that can be either wall or DIN rail mounted. Local Power distribution may provide additional breakers per circuit if required.

Q. What power requirements are required for Customer Terminal Card?

A. 20-70Vdc-250mA max.

(maximum current is only a peak at minimum supply voltage during ringing into maximum ring load.)

nominal current – 20mA @ 24Vdc

14mA @ 48Vdc

Q. What earthing is provided for the Customer cards?

A. NONE! Customer telephone circuit is powered from a double isolated charging system and the Customer card itself provides isolation within its internal power supply. This provides isolation for local low level surges that may exist during fault conditions. Conventional protection systems can be employed at the local MDF if required.

Exchange Enclosure

Q. What are the environmental ratings of the Enclosures?

A. The eLYTE enclosures are originally IP68 rated. But due to cabling requirements IP65 will be achieved under normal installation practices.cIP68 could still be achieved with alternative cable glands.

Q. What type of Phone cable should be used?

A. The incoming Exchange cable should be a continuous insulated length from the local exchange or demarcation point outside the EPR area.
Outdoor grade cable.
Preferable 0.63mm core diameter twisted pair that can cater for up to 20pairs,(two wires per IDC) but only 10 pairs can be utilised.
NOT recommended to use ARMORED cable!
Cable should be laid within a PVC, PE, HDPE, or similar insulated conduit. Refer AS/NZS3835.

Q. What termination method is available for the Exchange enclosure.
A. KRONE IDC connector provides termination for ten pairs. Test access is available by way of Krone Test Plug.

Customer Enclosure

Q. What type of Phone cable should be used?

A. Customer enclosure phone cable can be indoor grade CAT3 or better and wired to the local internal MDF.

Q. What type of breaker are installed in the DC distribution panel?

A. 1Amp DC rated din rail compliant Breakers. 10KA ‘B’ curve rated.
Breakers are also used as switches for decommissioning or installation processes.

Q. Why can’t standard AC breakers be used?

A. DC breakers are required to open a switch whilst current is flowing.
Conventional AC breakers can easily shut off at a 0 current point due to the AC cycle.
DC sources are typically battery supplies, which is a large source of readily available power. The DC batteries are capable of very high current flows, 1000’s of amps for up to a millisecond or more.
The DC breakers need to act on this HIGH energy flow quickly and cleanly. ‘B’ rated is a speed response rating required for all breakers. Typical AC breakers are ‘C’ curve.
The difference is in the order to 25 to 50 times slower than a B curve.

Power Supply Enclosure

Q. What are the AC requirements?

A. Only a low power AC mains is required for the battery charger. 200-265Vac 45-65Hz 0.35Aac max

Q. What capacity of power is available?

A. DAVAS provides a 24V 10Ahr energy source.

Duration of 3-4 hours if 10 circuits are utilized 100% of the time!

when entirely on standby the equipment will provide 24 hours of service without AC power. DAVAS can provide more capacity if required.

Q. What type of Fuse is Required for the Power Supply Enclosure?

A. 10A ATO (Automotive Blade type Fuse). Provided.

Q. What type of charger is provided?

A. DAVAS provides a 24V 5Amp IP65 rated intelligent charger. Charger includes reverse polarity, short circuit and over-temp protection.

Fiber Distribution Enclosure

Q. What types of fiber terminations are available?

A. The Distribution panel is made for up to 10 pairs of ST connections.

Other interface types are available.

Both Multi-Mode and Single-Mode patch bulkheads are available.

Isolation Switch Enclosure

Q. How does the isolation switch work?

A. The isolation switch is a 10 pair ganged switch. The switch contacts that close the gap between incoming and local exchange cards are separated by >20kV isolation gap. When opening the enclosure cover, the switch contacts are opened by physical removal of the switch blade, shutting down and isolating all incoming circuits in one operation.

Power Requirements

Q. What power requirements are required for Exchange Terminal Card?

A. None – exchange card is line powered by the incoming tip/ring from the telephone exchange.

Q. What power requirements are required for Customer Terminal Card?

A. 20-70Vdc-250mA max.

(maximum current is only a peak at minimum supply voltage during ringing into maximum ring load.)

nominal current – 20mA @ 24Vdc idle

14mA @ 48Vdc idle

Q. What power requirements are required for Enclosures?

A. Local mains supply is only required for the Power Supply enclosure that provides DC power to the Customer enclosure.

Local DC supply may be utilised as an alternative if available. 24 or 48Vdc would be required from a 5A distribution point.

Operating Temperature

Q. What Temperature range can the eLYTE equipment operate?

A. All DAVAS Equipment are designed to operate -10 to +50 Degrees Celsius ambient, up to 95% Humidity

More custom solutions can be catered for in environmental conditions that fall outside typical applications.

Card Dimensions

Q. What size are the DAVAS eLYTE cards?

A. Both eLYTE Exchange and Customer Cards and the Single Mode Adapter Card are the same physical size.

100mm x 85mm. With Fiber interface and minimum bend radius of fiber an additional 70mm of depth is required.

Total installed depth of 155mm

Compliant Approvals

Q. What compliance certificates does the DAVAS Isolation Equipment conform to?

A. All eLYTE equipment is tested by independent test authorities where applicable.


Australian requirements

A Tick- N1246 for eLYTE isolation cards- includes compliance to following standards.

AS/ACIF S002:2005 & S003:2005

AS/NZS 60950-1:2003 + A1:2006 + A2:2008 + A3:2008


C Tick- for eLYTE SMA cards- includes compliance to following standards.


New Zealand requirements

Telepermit- PTC210/06/003 for eLYTE isolation cards- includes compliance to following standards


AS/NZS 55022: 2006 Class A device

FCC part 15 sub-part A and B as Class A device

Additional standards

Enclosure system tested to AS/NZS 60950-1:2003 + A1:2006 + A2:2008 + A3:2008

Enclosure system designed to recommendations within AS/NZS 3835

Enclosure Isolation Switch has been independently tested to 25kV for 60 sec (20kV withstand)

Electrical Isolation

Q. What is the Isolation of the incoming line to the surrounding environment?

A. The Fiber based eLYTE isolation cards are capable of up to 100kV per meter of separation.

The isolation Switch has a physical distance of >45mm creep-age distance between incoming line terminals and a test finger probe.

Note. Test finger probe is a metal probe that is shaped and hinged to act as a persons finger. It is used to test if an operator can infiltrate a hazardous environment due to a hole in the outer case of a product or exposure to conductive components.

The Isolation Switch has been tested at 52uA leakage at 25kV between incoming terminated cable and finger test probe across the Isolation Switch Blade slot.

The hazardous components are mounted on a polycarbonate back-panel that is
in turn secured to the mounting posts of the polycarbonate enclosure. This process isolates the hazardous parts by physical distance and increased propagation distances for arcs to traverse.

Incoming cable insulation is achieved by the cable sheaf and the conduit housing the incoming cable from outside the EPR area.

Q. What is the isolation of the Customer card to local ground?

A. 1500V isolation is provided by the basic isolation of the Battery charger to battery terminals.

100V component between Tip/Ring ground and Battery supply for EMC purposes.

Audio Parameters

Q. What audio range is supported by eLYTE POTS?

A. Between 300Hz to 3400Hz.

Q. What Loss level is provided by eLYTE POTS?

A. 0dB ±0.5dB between 500Hz to 3200Hz

+0 to1.5dB 300Hz-500Hz

+0 to 3dB 3200Hz-3400Hz

Q. What Termination impedance is provided by eLYTE POTS?

A. Any typical POTS impedance can be provided for.

Typical impedance are..

TN12 for Australia

BT3 for New Zealand

600R for United States.

Return Loss

Q. What is the return-loss of the eLYTE POTS equipment?

A. By design,only terminal balance return-loss is relevant and achieves
>15dBm balance return-loss from 500Hz to 3200Hz
>12dBm from 300Hz-500Hz and 3200Hz-3400Hz
Figures >20dBm across the audio range is typical.

Overload Level

Q. What overload level is the eLYTE capable of sending?

A. eLYTE POTS can provide +3db transmission level is both directions.

Australian relative transmissions levels and nominal signal levels are adhered to for Australian model of -10dBm signal level, 0dBr exchange to Customer, -6dBr Customer to Exchange.

New Zealand model capable of +3dB transmission levels and nominal signal levels are adhered to for New Zealand model of -10dBm signal level, 0dBr exchange to Customer, 0dBr Customer to Exchange.


Q. What noise levels are generated from eLYTE POTS cards?

A. eLYTE POTS provides <-65dBmOp noise levels, typically -70dBmOp. dBmOp denotes decibel power level psophometric weighting.

Customer Telephone Feed

Q. What voltage feed is provided by Customer card?

A. Line feed Voltage is typically 40Vdc but could be as high as 46Vdc.

Q. What range can the Customer card provide service?

A. Typically 4.4km. As per many telephone feeds provided by the local exchange.

Dialing Method

Q. What dialing method can be used?

A. DTMF only. DAVAS eLYTE does not cater for decadic or pulse dialing.


Q. How many phones can the Customer Card Ring into?

A. eLYTE Customer card provides >55Vrms ringing into 2u2+10k ring-load. A typical electronic phone ring-load.

Up to 5 electronic ring loads can be across tip/ring.

Q. What ring frequency is generated by the Customer Cards?

A. eLYTE POTS isolation system replicates the incoming ringing frequency and cadence from 16 to 25Hz.

Q. What ring load does the Exchange card provide?

A. Different test authorities test under different criteria and refer to this number different ways.

So DAVAS has provided all versions of this ring load figure including the actual reactive load.


RN= 0.5 from New Zealand.

REN=0.1 from Australia.

Line Resistance

Q. What loop distance can the Exchange operate?

A. Approximately 4.4km with a 48V feed.

Depending on copper gauge and condition 10V @ 20ma gives a 2400Ω loop resistance from a 48V exchange feed.
Given a 24V line feed a 1200Ω loop can be serviced.

Q. What standby resistance does the Exchange represent?

A. The Exchange card provides >1Meg resistance at 48Vdc when in the on-hook condition. Or approximately 20uA

Surge Protection

Q. What Surge protection Does the Exchange Card provide?

A. Due to the isolated nature of the Exchange card, any protection methods that employ a direct path or reference to local ground will cause catastrophic failure of the local exchange equipment and incoming copper line.

eLYTE Exchange Card does provide differential protection of the incoming TIP/RING pair by way of MOV/PTC/DIAC protection to clamp incoming differential surges and limit subsequent loop current.

Q. What Surge protection Does the Customer Card provide?

A. As with the Exchange Card and due to it’s isolated nature it provides the same type of differential protection that the Exchange Card.

Any local protection scheme should be installed within the local MDF.

Fiber Cable Types

Q. What fiber types are available?

A. eLYTE Isolation and associated products can provide 2mm plastic fiber, Glass fibers including stepped, graded and Single-Mode fibers, sizes including 9um, 50um, 62.5um and 200um core diameters.

Q. What type of fiber interfaces can be catered for?

A. eLYTE Plastic fiber interface utilizes a combination of ‘Agilent Versatile Link’ interface and an ‘TE-Connectivity Sweetspot’ coupling on the exchange card. (due to design performance requirements the Exchange card requires a custom pin-diode receiver).

Both Multi-Mode and Single-Mode interfaces use ST patch cables.

Q. Can I use other fiber interfaces like LC,SC or FC for glass fiber interfaces?

A. Although DAVAS equipment utilizes only ST connections, the end customer can use patch cable adapters to their preferred interface type. Contact DAVAS for alternative patch panel solutions.

Transformer solutions

Q. Can DAVAS provide a transformer based protection system?

A. Yes we can! DAVAS can provide a transformer solution for many DSL technologies.

But you are limited in protection level to the rating of the lowest rated isolation transformer that is across the isolation barrier.

Failure condition of an isolation transformer is unclear. If the barrier breakdown threshold is compromised within the transformer you may not be aware of the fault until it fails completely and damages local and/or remote equipment.

DAVAS recommends a testing schedule to identify at risk transformers.


Q. Can you provide isolation for ADSL/ADSL2+ circuits?

A. Yes. With a combination of eLYTE POTS and a Broadband 20kV isolation transformer DAVAS can provide the reliability of a POTS circuit independent of ADSL functionality.

No ADSL filter required.

(Note Use of isolation transformers for protection will limit the entire site isolation threshold to that of the isolation transformer.)

Transformers capable of HDSL and VDSL technologies are avaialble.

Q. what other DSL technologies can be provided over fiber isolation?

A. Only technologies than provide line powering, (span power) can utilize fiber isolation. Technologies like HDSL which can provide a DC loop current from the telephone exchange can power the optical circuitry to provide the isolation required.

See DAVAS UHDSL product for fiber isolated DSL solution.

Installation Requirements

Q. What is required for eLYTE installation?
A. A wall. Dimensions vary due to fiber requirements but as little as a bare wall with 0.4m wide by 0.5M high will allow installation of one equipment enclosure and associated cabling.
Can be secured to any flat surface, 1meter above the floor as per AS/NZS 3835.
Incoming exchange cable must be secured within a PVC pipe that can be adjusted to suit the installation.
NOTE exchange enclosure should be clear of any other equipment or building structure within a diameter of 2 meters of the exchange enclosure. Refer to standard AS/NZS 3835

Q. Are isolation mats/procedures required when working on the Exchange enclosure?

A. Although the design of the enclosure automatically isolates the incoming lines from any surrounding equipment. It is still recommended to employ isolation procedures as described in AS/NZ 3835 when working on the Exchange enclosure.

When initial installation and termination of exchange enclosure or if the isolation switch within the enclosure is opened for installation purposes then isolation methods MUST be employed.

Lightning Surge Protection

Q. What lightning surge protection is required for the exchange cards?

A. None! any lightning protection attempts to redirect a lightning strike to earth as directly as possible. eLYTE isolation equipment isolates the surrounding environment from the incoming telephone line.

Q. What lighting surge protection is required for the Customer cards?

A. This is dependent on size of installation and distance Customer circuits are expected to provide service. Lightning protection is not provided for within the eLYTE solution but can be installed with other protection methods at the end users termination point or MDF.


Q. What Earthing is required.

A. No earthing required for eLYTE solutions

Earthing systems can be employed at Customer MDF if required for local protection.

DC supply can be tied to ground circuit if required.

AC charger utilizes an Earth for its own case protection.

Safety Procedures

Q. What safety procedures are required.

A. Safety practices detailed in AS/NZS 3835 should be employed for personnel safety. Use of insulating mats or platforms, insulated gloves and tools.


Q. What range of fiber can the eLYTE solution operate over?

A. Plastic fiber installations are capable of about 20m of fiber distance.

Multi-Mode Glass Fiber is capable of about 1500m.

Detail calculation will be required due to the type of fiber installed, ie. some types of fiber could allow Multi-Mode eLYTE to operate up to 3km of fiber.

Single-Mode Glass Fiber is limited to 1.6km or 6dB of fiber attenuation. This is due to a limitation of the Exchange transmit power available due to the energy used for Single-Mode devices.

DAVAS can provide a SMA or Single-Mode Adapter that converts the plastic fiber model to a Single-Mode fiber interface capable of 70km if needed.

Single-Mode installations are generally only introduced if Single-Mode fiber is readily available and laying Multi-Mode fiber would be cost prohibitive