Worksheet 7 - System Power Factor Check - Toshiba STRATA DK14 Installation And Maintenance Manual

Worksheet 7 – System Power Factor Check
The Strata DK power supply was engineered for maximum cost efficiency to provide power for
the most configurations. Because of this design, some -24VDC power limitations exist when using
old electronic-type telephones and/or telephone option hardware. Also some +5VDC power
limitations exist when using RWIU PCBs.
Each telephone/device and PCB has been assigned Power Factors (PFs) that reflect the amount of
power supply resources they consume. The Power Supply Unit has also been assigned Power
Factors that reflect how much power it can supply. To make sure the cabinet power supply is
operating within its limit, it is necessary to add up the PFs of each telephone/device and PCB
installed in each cabinet to verify that their total PFs do not exceed the Power Supply PF.
Use the work sheets provided on
limits.
Important Power Factor Considerations
o The individual PCB and telephone power factors can be found on
o The sum of all PCB and telephone –24VDC PFs in a given cabinet cannot exceed 85.
o The sum of all PCB +5VDC PFs in a given cabinet cannot exceed 40; telephones do not have
+5VDC PFs.
It is only necessary to check the +5VDC PF of a cabinet if RWIU PCB(s) are installed.
o
If a cabinet PF is exceeded it is necessary to reconfigure the cabinet to meet PF limits.
o
o If a cabinet's Power Factor is exceeded, cabinet or connected peripherals may malfunction
during ringing or voice paging, whereas normal operation will occur for idle telephones.
o The DK424i, PSUB672 power supply provides a PF alarm LED and reset button. If this LED
is on, reset it with the reset button. Then recheck the cabinet PFs to make sure they are within
limits.
PCB Power Factor calculation examples are shown in
Note
Table 6-22 Strata DK424i Base Cabinet
PDKU
RBSU + RBSS
RCOU + RCOS
B1CU
BRCS1A-4
RWIU
Strata DK I&M 6/00
Pages 6-35~6-37
PCB Quantity
2
1
1
1
1
1
Total 7
Worksheet 7 – System Power Factor Check
to calculate that each cabinet PF is within
Pages 6-34
Tables 6-22 and 6-23.
+5VDC PF -24VDC PF
1.6 0.6
3.1 0.3
3.6 4.0 (8 COs)
2.0 1.0
0.4 0.3
9.2 0.0
19.9 6.2
DK424i Configuration
and 6-35.
6-33