Cabling the Power Filter Units

This chapter provides information and instructions for applying the power feed and return cables to the Power Filter Units (PFUs) and the chassis.

Power Considerations

Each chassis supports up to two PFUs. There are two versions of the PFU:

l	125 Amp: The circuit breaker on this PFU is rated at 125 amps.

l	165 Amp: The circuit breaker on this PFU is rated at 165 amps.

CAUTION: 125A and 165A PFUs are not interchangeable.

Verify that the PFUs are correct for the chassis. The chassis part number label located in the rear center of the chassis just above the PFU slots identifies the proper PFUs to be used.

The following table describes the power requirements for the chassis.

 

Chassis Power Requirements

Characteristic	Value
Input Voltage	Maximum range: -40VDC to -60VDC Nominal range: -48VDC to -60 VDC
TUV Rated Peak Current Load	73A @ -48 VDC
Maximum Peak Power Load	3504W
Chassis Max Power Load	800W
Line Card (rear-installed) Max Power Load	SPIO: 15W Ethernet 10/100: 13.5W Ethernet 1000: 10.5W RCC: 20W
Application Card (front-installed) Max Power Load	SPC: 110W PAC: 130W

Estimating Power Requirements

Use the following formula to estimate the total power consumption for each deployed chassis:

(Total Application Card Max Power Load) + (Total Line Card Max Power Load) + (Chassis Max Power Load)

The calculation for estimating the power required for an ST16 installation with 3 PACs, 2 SPCs, 2 SPIOs, 2 RCCs, and 4 Ethernet 1000 line cards is as follows:

(250W x 3) + (180W x 2) + ((15W x 2) + (20W x 2) + (13.5W x 4)) + 800W = 2034W

 

Power Cable Requirements

You can install up to three chassis in an equipment rack or telecommunications cabinet. It is recommended that you run the power cabling to the rack or cabinet and then to each of the chassis through a fuse panel installed in the rack. Due to the required bending radius at each of the system’s PFUs, distributing power through a fuse panel allows you to use a smaller, more flexible cable for each chassis.

The following table identifies the recommended cable gauges you should used.

 

Recommended Cable Gage Information

Platform

Gage Information

ST16

n Each cable between the PDF and fuse panel must be the equivalent of 207,200 (208,000 rounded) circular mils (0000 AWG) or greater. n This assumes a 70 foot loop length. n Calculations were made assuming a 0.3 volt drop from the PDF to the fuse panel, and a 0.3 volt drop from the fuse panel to the chassis. This is a total voltage drop of 0.6 volts. n Each cable between the fuse panel and the chassis must be the equivalent of 35,520 circular mils (4 AWG) or greater. It is recommended that high-flex cable be used. n This assumes a 12 foot loop length. n Calculations were made assuming a 0.3 volt drop from the PDF to the fuse panel, and 0.3 volt drop from the fuse panel to the chassis. This is a total voltage drop of 0.6 volts. Figure 9-1 and Table 9-3 provide a diagram and details for wiring the system’s PFUs.

ST16 PFU Wiring Diagram

 

ST16 PFU Wiring Diagram Descriptions 

Item	Description
1	125A PFU Power Terminal: Dual 2-hole lugs required: one for return (RTN) and one for power (-VDC). PFU has 0.250-inch posts D, spaced 0.63-inch on center. Method of connection: PFU - Flat Washer - Lug - Flat Washer - Nut (7/16-inch). The nut(s) must be torqued to 50 in-lb. (5.65 n-m). Recommendations: n Use Panduit® lug type LCCF4-14A-L with Panduit crimp tool part number CT-920 (die color: gray P29 (CD-920-4). n The lug must be covered with heat shrink. The heat shrink should begin approximately 1 inch (25.4 mm) before the lug and extend to within 0.5 inch (12.7 mm) of the lugs first hole. Refer to Figure 9-2 that follows. The plastic terminal cover must be installed over power and return lugs at all times. Die angeschlossenen Kabelschuhe muessen mit der Plastikabdeckung gesichert sein.   165A PFU Power Terminal: Dual 2-hole lugs required: one for return (RTN) and one for power (-VDC). PFU has 0.3125-inch posts D, spaced 0.88-inch on center. Method of connection: PFU - Flat Washer - Lug - Lock-Washer - Nut (9/16-inch). The nut(s) must be torqued to 50 in-lb. (5.65 n-m). Recommendations: n Use the Panduit® lug supplied with the chassis (LCD4-56C-L) with Panduit crimp tool part number CT-920 (die color: gray P29 (CD-920-4). The LCD4-56C-L lug is a custom lug. Please contact your local sales or service representative with any questions. n The lug must be covered with heat shrink. The heat shrink should begin approximately 1 inch (25.4 mm) before the lug and extend to within 0.5 inch (12.7 mm) of the lugs first hole. Refer to Figure 9-2 that follows. The plastic terminal cover must be installed over power and return lugs at all times. Die angeschlossenen Kabelschuhe muessen mit der Plastikabdeckung gesichert sein.
2	Power Cables (Fuse Panel-to-Chassis): Cable length: Not more than 6 feet (1.829 meters) one way Voltage drop: 0.3v Cable size: 4 AWG or greater
3	Power Cables (PDF-to-Fuse Panel): Cable length: not more than 35 feet (10.668 meters) one way Voltage drop: 0.3v Cable size: 208,000 circular mils - 4/0 or greater

 

Power Lug Details

Connecting the PFU to the Power Source

Follow the instructions in this section to connect your system’s 125A or 165A PFU(s) to the power supply.

Each of the four power terminals is shipped with nuts and washers. The 165A PFU has one lock-washer and one flat washer. The 125A PFU has two flat washers.

WARNING: To avoid electric shock, ensure that the power source is off before attaching power cables to the PFU(s) installed in the chassis.

Spannungsversorgung abschalten vor Anschluss der Kabel an die Netzteile, um einen elektrischen Schlag zu vermeiden.

1	Ensure that the PFU in the bay labeled Power Filter Unit 1 is in powered off.

a	Flip the circuit breaker actuator to the OFF position.

b	Optional. If the circuit breaker on your PFU is equipped with a locking clip, lock the circuit breaker in place: move the breaker’s locking clip to the right until the clip’s inside tang is recessed in the breaker’s actuator opening.

2	Remove the plastic cover from the power terminals with a #2 Philips head screw driver.

3	Remove the nut and the lock-washer on the 165A PFU, or the nut and flat washer on the 125A PFU, from each of the four terminals. The nuts on the 165A PFU require a 9/16-inch nut driver or socket wrench; those on the 125A PFU require a 7/16-inch nut driver or socket wrench.

4	Fasten the lug attached to the power return cable to the PFU:

a	Insert the lug over the two terminals labeled RTN. These are the two top terminals on the PFU.

b	Secure the lug to the RTN terminals with two of the four washers and two of the four nuts that you removed in step 3. The nuts should be torqued to 50 in-lb. (5.65 n-m).

5	Fasten the lug attached to the power feed cable to the PFU:

a	Insert the lug over the two terminals labeled -VDC. These are the two bottom terminals on the PFU.

b	Secure the lug to the -VDC terminals with the remaining two washers and nuts that you removed in step 3. The nuts should be torqued to 50 in-lb. (5.65 n-m).

WARNING: To avoid the risk of fire, take proper precautions to ensure that the power feed and return lugs are not touching.

Um einen Kurzschluss zu vermeiden, duerfen sich die beiden Stromkabel nicht beruehren. Kabelschuhe duerfen sich nicht beruehren und muessen unbedingt auseinander gehalten werden.

6	Reinstall the plastic terminal cover.

CAUTION: To avoid the risk of electric shock and/or potential damage to the system, never operate the chassis without the plastic terminal cover. In addition, make sure the power and return lugs do not protrude past the edge of the plastic terminal covers. Any portion of the lug that is exposed must be covered with shrink wrap.

7	Repeat step 1 through step 6 for the PFU installed in the bay labeled Power Filter Unit 2.

8	Proceed to the next chapter for information and instructions on applying power to the chassis and verifying that the installation was successful.

Cisco Systems Inc.

Tel: 408-526-4000

Fax: 408-527-0883