JDS Uniphase SmartClass - DC Current; Longitudinal Balance

Chapter 16 Test Results
Copper results
SmartClass TPS User’s Guide
136 22035456, Rev 001 June 2014
– measure total electrical loop length (includes length of bridged taps).
– find wet sections, bridged taps or open faults.
Opens/Capacitance: < 3% difference between Tip (A) and Ring (B) values indicate an acceptably
balanced loop. Anything greater indicates an unbalanced line or open fault, which inhibit digital
signals.
Table 49 describes the opens/capacitance result.
DC current
You measure DC current to verify if enough current is present to operate equipment including the
phone or caller ID boxes.
DC current on Tip (A) to Ring (B) should be  23 mA at the NID. Anything less will not allow for differ-
ences in temperature and phone equipment will not operate during extremes.
Table 50 describes the DC current result.
Longitudinal balance
You measure longitudinal balance to:
– measure the quality of the pair: a measurement of the degree to which the Tip (A) lead is elec-
trically the same as the Ring (B) lead.
The more each lead is electrically identical (capacitance, inductance, impedance), the better the
pair will resist induced noise.
The balance result should be >60 dB. Anything less indicates electrical differences between Tip (A)
and Ring (B) that can lead to noise and other signal problems.
Table 51 describes the DC current result.
Table 49 Opens/Capacitance result specifications (no ambient)
Range (feet)
Resolution
(feet)
Range (meters)
Resolution
(meters)
Range
(capacitance)
Accuracy (applies to
capacitance only)
0 to 2,999 1 foot 0 to 999 0.1 meter 0 to 44.9 nF 3% ± 45 pF
3000 to 66000 1 foot 1,000 to 20,000 0.1 meter 45 nF to 1.04 µF 3%
Table 50 DC current result specifications
Range Resolution Accuracy
0 to 110 ma 1ma 2% ± 1ma
Table 51 Balance result specifications
Range Resolution Accuracy
35 to 70 dB 1 dB 2 dB