ADC HDSL4 user manual Power Consumption, Maximum Power Dissipation, H4TU-C Power Parameters

Appendix A - Specifications LTPH-UM-1031-03, Issue 3

POWER CONSUMPTION

The three most important power parameters of an H4TU-C are its maximum power consumption, maximum power dissipation, and maximum current drain.

Table 20 describes line-powered and locally powered (remote) circuits on the maximum reach condition (34 kft.) using 26 AWG wire.

Table 20. H4TU-C Power Parameters

		-48 Vdc Power Consumption		Heat Dissipation (Watts)		-42.5 Vdc Current (mA)
			(Watts)
Number of	Remote Power	Typical	Maximum	Typical	Maximum	Typical	Maximum
Doublers	Source
None	Locally powered	7.6	8.4	5.9	6.4	179	197
None	Line-powered	11.0	12.1	6.2	6.8	259	285
1	Locally powered	14.6	16.1	6.6	7.2	344	378
1	Line-powered	20.0	22.0	7.1	7.8	471	518
2	Locally powered	26.7	29.4	8.4	9.2	628	691
2	Line-powered	32.9	36.2	9.3	10.3	774	852

MAXIMUM POWER DISSIPATION

The maximum power dissipation measures the power converted into heat which builds up within the unit. It contributes to the total heat generated in the space around the unit. It is used to determine the maximum number of fully loaded shelves per bay that does not exceed the maximum allowable power dissipation density in watts per square foot to comply with GR-63.

In COs, the maximum power dissipation for open-faced, natural convection-cooled mountings is limited to

134.7watts per square foot per GR-63-CORE. Use this limit and the parameters in Table 21 on page 61 to determine the maximum number of H4TU-C circuits that can occupy one CO bay.

This is a worst case situation since it assumes the entire CO is subjected to the maximum power density. More favorable conditions would permit increasing the number of shelves per bay without jeopardizing the CO thermal integrity.

The thermal loading limitations imposed when using the H4TU-C in a Controlled Environmental Vault (CEV) or other enclosures are determined by applying its power parameters to the manufacturer's requirements for each specific housing.

The -48 Vdc power consumption is the maximum total power that the H4TU-C consumes or draws from the shelf power source. This parameter is needed when the H4TU-C is in a location remote to the CO it is serving. It determines the battery capacity required to maintain an 8-hour, standby battery reserve for emergency situations. Battery capacity, therefore, limits the maximum number of line units which can be installed in a remote enclosure. Use the data in Table 21 to perform this analysis.

60 September 12, 2003 H4TU-C-319 List 1