Specifications

Chapter 5: Installation
Station Loop Resistance Test
Mitel
®
5000 Installation Manual – Issue 3.0, October 2008 Page 5-85
Station Loop Resistance Test
Do not use shielded cable. Achieve longer loop lengths by using heavier gauge cable, such as
22AWG. (For additional station cabling requirements and loop limits, see page 5-20.)
Perform the loop resistance test for each station cable individually.
1. With a U.S. system only, ensure that bridging clips have not been installed on the station
blocks and that the station instrument is not connected to the modular jack assembly.
2. With a U.S. system, place a short across the BLACK/YELLOW wires (endpoints) or
RED/GREEN wires (single line endpoints) on the modular jack assembly.
With a European system, place a short across the WHITE/BLUE wires (endpoints) or
BLUE/WHITE wires (single line endpoints) on the line jack unit assembly.
3. With a U.S. system, at the MDF, measure the resistance across the TIP and RING wires
on the right (station) side of the station block.
With a European system, at the MDF, measure the resistance across the WHITE/BLUE
wires on the lower (station) side of the station block.
The reading should not exceed the limits listed in Table 5-12. The resistance values (in
ohms) indicate loop measurements; the distance values (in feet/meters) indicate the
maximum one-way measurements from the equipment chassis. If necessary, longer loop
lengths can be achieved by using a heavier gauge cable, such as 22 AWG (22 gauge
thickness or larger—smaller number gauge = larger, or thicker, diameter).
4. Remove the short after the test is complete.
5. Repeat this test for each station cable.
6. With a U.S. system only, install bridging clips on the station blocks to complete the cable
connections.
Table 5-12. Loop Limits for Digital and Single Line Endpoints and Equipment
IMPORTANT
Excessive and/or improperly made connections increase the
resistance of a cable, which reduces the allowable cable run length.
Endpoints
Port
Impedance
Loop Limit
(24 AWG)
From Base Server chassis:
• To a single line endpoint or playback device connected to the
built-in port
• To a single line endpoint or playback device driven by a
SLM-4 port
From DEI chassis: To a single line endpoint or playback device
driven by a SLM-8
600
Ω 2000 ft
(609 m)
REN 3.0
From DEI chassis:
• To digital endpoints
• To a digital endpoint equipped with PCDPM and MDPM and
connected to DSS unit(s) or SLA
62
Ω 1200 ft
(366 m)
From an MDPM: To a single line endpoint 195
Ω 3800 ft
(1158 m)
From an SLA: To single line endpoints or playback devices.
Supports facility code OL13C.
800
Ω 15,560 ft
(4742 m)