4. Special Test Circuits
The special test circuits required to perform the tests described in Section 3 are shown in schematic form in this section.
4.1 Loop Simulator for Loop-start and Ground-start Circuits
Figure 4.1 — Loop Simulator for Loop-start and Ground-start Circuits
Condition | V, volts | Switch Position for Test | R + RL |
---|---|---|---|
1 | 42.5 to 52.5 | Both | Continuously variable over 400 to 1740 Ω |
2 | 105 | (b) | 2000 Ω |
Notes:
- Means shall be employed to generate, at the point of tip and ring connections to the terminal equipment (TE) protective circuitry, the parameters of DC line current and AC impedance which are generated by the illustrative circuits described above (as appropriate for the equipment under test).
- In performing the longitudinal balance (Section 3.6), the use of the "DC portion of the loop simulator circuit" is specified.
4.2 Loop Simulator for Reverse Battery Circuits
Figure 4.2 — Loop Simulator for Reverse Battery Circuits
R + RL = Continuously variable over 400 to 2450 Ω
Notes:
- Means shall be employed to generate, at the point of tip and ring connections to the TE protective circuitry, the parameters of DC line current and AC impedance which are generated by the illustrative circuits described above (as appropriate for the equipment under test).
- In performing the longitudinal balance (Section 3.6), the use of the "DC portion of the loop simulator circuit" is specified. In such cases, components C1 and C2 shall be removed.
4.3 Loop Simulator for 4-Wire Loop- and Ground-start Circuits
Figure 4.3 — Loop Simulator for 4-Wire Loop- and Ground-start Circuits
Condition | V, volts | Switch Position for Test | R2 + RL |
---|---|---|---|
1 | 42.5 to 52.5 | (a) and (b) | Continuously variable over 400 to 2450 Ω |
2 | 105 | (b) | 1740 Ω |
4.4 Loop Simulator for 4-Wire Reverse Battery Circuits
Figure 4.4 — Loop Simulator for 4-Wire Reverse Battery Circuits
Note: R2 + RL = Continuous variable over 400 to 2450 Ω.
4.5 DC Conditions to Off‑Premises Stations (OPS) Lines
Figure 4.5 — DC Conditions to Off‑Premises Stations (OPS) Lines
Note: The minimum DC current present for all resistance ranges of conditions 1 and 2 shall be 16 mA, as per the following table:
R + RL Continuously Variable over the Following Range | ||||
---|---|---|---|---|
Condition | Switch Position for Test | Class A | Class B | Class C |
1 | (a) | RL to 200 Ω | RL to 800 Ω | RL to 1800 Ω |
2 | (b) | Not Applicable | 200 to 2300 Ω | 900 to 3300 Ω |
Notes:
- Means shall be used to generate, at the point of tip (T OPS) and ring (R OPS) connections to the PBX, the range of the resistance and impedance which are employed by the illustrative circuit depicted above.
- For the longitudinal balance (Section 3.6), the use of the "DC portion of the line simulator" is specified. In such cases, components C1 and C2 shall be removed.
4.6 Alternative Off-hook Termination
Figure 4.6 — Alternative Off-hook Termination
Note: This alternative termination is used to replace 600 Ω.
4.7 E&M Signalling
4.7.1 TE on Side "A"
Figure 4.7.1 — E&M Types I & II Signalling (TE Originates on M Lead)
4.7.2 TE on Side "B"
Figure 4.7.2 — E&M Types I & II Signalling (TE Originates on E Lead)
4.8 Reference Information
4.8.1 Reverse Battery Trunk Interface
Direct inward dialing (DID) TE interface functions are interpreted as follows:
Tones | Answer Supervision | Failure Mode Supervision | |||
---|---|---|---|---|---|
TE Response/Condition for Incoming Calls | Busy 60 IPM | Reorder 120 IPM | Required | Not Required | Reverse Battery or Control Circuit Interface |
If the station answers | X | ||||
If the call is answered by an attendant, a recorded announcement or other means | X | ||||
If the number is busy | X | X | |||
If all transmission paths in the TE are busy | X | X | |||
If the TE returns ring back tone to the caller | X | ||||
If all incoming trunks to the TE are busy | N/A | The network will indicate all-trunks-busy to the caller N/A. | N/A | ||
If the TE is out of service due to: maintenance, power failure, power disconnected or other malfunctions or conditions | The network will indicate all-trunks-busy to the caller. (See Footnote Note 1.) | X | |||
If the terminal TE returns dial tone to the caller (see Footnote Note 2) | X |
Footnotes
- Footnote 1
-
This condition is the result of failure mode supervision from the TE.
- Footnote 2
-
Applicable to a TE that is arranged to return a dial prompt to the calling party for the purpose of accepting further dialled digits that may be used to re-route the incoming call to another destination.
See also Section 3.5.4 for more information on direct inward dialing.
5. Terminal Equipment (TE) Installation Wiring
Note:
This section is for information purposes only and does not form part of the mandatory requirements.
5.1 Scope
This section provides guidelines for the installation and wiring of technical equipment (TE) when the installation of such equipment requires inside or in-building wiring that is not an integral part of the equipment as registered. Such installation shall be carried out under the supervision of qualified personnel and shall be in accordance with the guidelines of this section to ensure that registration requirements are met once the TE is connected to the network.
5.2 General
TE and all associated installation wiring could, under certain circumstances, become exposed to extraneous voltages, current and surges from the network and from connections to other equipment. For example, they could be subjected to lightning-induced voltage surges of up to a 1000 V peak. The average rise time of such a surge is 100 μs. The minimum rise time can be less than 10 μs. The customer is responsible for ensuring that TE is normally connected to inside or in-building wiring.
There may also be times when the TE and all associated installation wiring may be subjected to voltages and current resulting from contact with commercial power facilities under fault conditions. There should be sufficient high impedance between the tip and ring and ground reference to allow the metallic and longitudinal voltages to rise at approximately the same rate as a lightning surge. TE and the associated installation wiring should be capable of safely withstanding these extraneous voltages, currents, and surges. It shall be installed in a manner that ensures continued compliance with the network protection requirements described in Section 3.
5.3 Safety Requirements
The installation of the TE and associated wiring shall be in accordance with the most recent version of the Canadian Electrical Code — Part I (issued by the Canadian Standards Association, which is the standard used to specify safety requirements for electrical installations).
5.4 Technical Requirements
5.4.1 Demarcation Point
The demarcation point, as defined in the CRTC Telecom Decision 99-10, is the physical location ("point") where the wires and facilities on one side of the point are under the responsibility and control of one party, while the wires and facilities on the other side of the point are under the responsibility and control of a different party. For single residences, the demarcation point is at the carrier-provided jack which shall be installed at an accessible location mutually agreed upon by the carrier and the customers. For multiple-dwelling units, in-building wiring may be owned by a telecommunications service provider or the property owner. Installation practices may vary depending on the type of building.
5.4.2 Type of Wiring
Wires, cables and connecting devices used in the installation shall be of a type designed for use in telecommunications applications and shall be suitable for the location and conditions under which they are used. The manufacturer's published recommendations of either the wiring or TE shall be considered sufficient indication of suitability. Examples of good installation practices may be found in CSA Standards T525-94 (R1999), Residential Wiring for Telecommunications, and T568.1-05 (R2010), Telecommunications Cabling Systems in Commercial Buildings.
5.4.3 Limitations on Wiring
The total loss of the TE and the wiring from the demarcation point to the furthest TE should be limited by the following conditions:
- if TE is intended for connection to CO lines:
- added resistance of 50 Ω; and
- transmission loss of 0.5 dB.
- if TE is intended for connection to trunks:
- no added resistance; and
- transmission loss of 2.5 dB.
Where the above limits are insufficient to meet the customer's requirements, the customer shall contact the service provider to determine jointly whether the particulars of the proposed installation will ensure minimum transmission specifications. In the event that transmission compensation is required, the customer may incur additional charges.
5.4.4 Communications Ground
In order to minimize the introduction of noise, TE requiring a communication ground separate from the safety (green wire) ground shall have a low-impedance path to the main building ground source, independent of that provided by the carrier for its equipment.
Note:
In locations where the local building ground potential may be expected to rise to hazardous levels relative to a remote ground, due to the proximity of an electric power station or similar installation, engineering coordination with the carrier shall be required.
5.5 Qualifications of Installation Supervision
The person responsible for the direct supervision of the personnel performing the installation shall have the necessary qualifications outlined in the appropriate documents.