Table of Contents

Chapter 3 Installation Preparations. 3-1

3.1 Safety Precautions. 3-1

3.1.1 General Safety Recommendations. 3-1

3.1.2 Electrical Safety. 3-1

3.1.3 Handling Safety. 3-1

3.1.4 ESD Damage Prevention. 3-2

3.1.5 Laser Safety. 3-3

3.2 Examining the Installation Site. 3-3

3.2.1 Temperature/Humidity Requirements. 3-3

3.2.2 Cleanness Requirements. 3-3

3.2.3 EMI Requirements. 3-4

3.2.4 Grounding Requirements. 3-4

3.2.5 Power Supply Requirements. 3-4

3.3 Installation Planning. 3-5

3.3.1 Installation Space Requirement 3-5

3.3.2 Cabinet-Mounting Requirements. 3-5

3.4 Installation Tools. 3-6

 

Chapter 3  Installation Preparations

3.1  Safety Precautions

To avoid bodily injury and device damage, please read the following safety recommendations carefully before installing the S7500 series. The recommendations do not cover every possible hazardous condition.

3.1.1  General Safety Recommendations

l           Keep the chassis clean and dust-free.

l           Keep the chassis and installation tools away from walk areas.

l           Do not wear loose clothing, jewelry (including ring and necklace, and so on), or any other things that could get caught in the chassis when you install or maintain the switch.

3.1.2  Electrical Safety

l           Look carefully for possible hazards in your work area, such as ungrounded power extension cables, missing safety grounds, and moist floors.

l           Locate the emergency power switch in the room before installation so that you can shut the power off at once in case of an electrical accident.

l           Unplug all external cables before moving the chassis.

l           Avoid maintaining the equipment alone when it is powered by electricity.

l           Never assume that power is disconnected from a circuit. Always check.

l           Do not place the switch on a moist area or let liquid flow into it.

3.1.3  Handling Safety

Since the S7500 series are rather large and heavy, you should follow the recommendations below.

l           Disconnect all power and all external cables (including power cables) before carrying or moving the chassis.

l           Ask somebody to move the switch together.

l           Move the switch slowly and stably.

l           Keep in step with your partner and balance your bodies when moving the switch.

 

 

3.1.4  ESD Damage Prevention

To prevent electronic components of the switch from being damaged by electrostatic discharge (ESD), you should not only take measures against ESD damage where the switch is located, but also take the following precautions:

l           Always wear an ESD-preventive wrist strap when installing components, especially boards of the switch.

l           Hold the bottom or ejector levers when installing or removing a board. Do not touch any electronic component or PCB.

Take the following steps to use the ESD-preventive wrist strap.

1)         Wear the ESD-preventive wrist strap and ensure it makes good skin contact.

2)         Insert one end of the ESD-preventive wrist strap into the ESD-preventive wrist strap hole in the switch chassis or use an alligator clip to attach the other end to the grounding screw on the chassis, making sure that the ESD-preventive wrist strap is well grounded.

 

 

 

3.1.5  Laser Safety

Some LPUs of the S7500 series have optical ports. If such an LPU is operating, do not stare into open optical ports because laser beams emitted from these optical ports will produce high energy, which may hurt your eyes.

3.2  Examining the Installation Site

The S7500 series are designed for indoor installation. To ensure the normal operation of the switch and prolong its service life, you should make the installation environment meet the requirements below.

3.2.1  Temperature/Humidity Requirements

To ensure the normal operation and service life of a switch, the temperature and humidity in the equipment room should maintain at a certain level. A long-term high relative humidity will quite likely result in poor insulation performance, electric leakage, mechanical property change, and corrosion, while a low relative humidity will result in looseness of fastening screws owing to shrinkage of insulation washers, or electrostatic discharge (ESD), which may damage the circuitry on the switch. A high temperature will speed up the aging of insulation materials, and thus will greatly lower the reliability of the switch and shorten the service life.

Table 3-1 Temperature/humidity requirements

Specification	Range
Operating temperature	0°C to 45°C (32°F to 113 °F)
Relative humidity (noncondensing)	10% to 90%

 

3.2.2  Cleanness Requirements

Dust is harmful to the normal operation of the switch. Dust on the chassis may result in static adsorption, which causes poor contact between metal connectors or points. Poor contact may not only shorten the service life of the switch, but also bring about communication failures. Especially under the condition of a low indoor humidity, dust adsorption is apt to occur.

Table 3-1 lists the requirements on dust content limit and diameters in the equipment room.

Table 3-2 Limitation on dust content and diameters in the equipment room

Mechanical active material	Content limit (particles/m³)
Dust particle	≤3 x 104 (No visible dust on desk over three days)
Note: Dust particle diameter ≥ 5µm

 

Besides, the contents of salt, acid, and sulfide in equipment room shall be strictly restricted. Harmful gases will accelerate the corrosion and aging of metal parts. Table 3-3 lists the content limit of SO₂, H₂S, NH₃, and CI₂ in the equipment room.

Table 3-3 Content limits on some harmful gases in the equipment room

Gas	Maximum (mg/m3)
SO2	0.2
H2S	0.006
NH3	0.05
Cl2	0.01

 

3.2.3  EMI Requirements

All possible interference sources, external or internal, affect the switch in the way of capacitance coupling, inductance coupling,  electromagnetic radiation, and common impedance (including the grounding system) coupling. To minimize the influence of interference sources on the switch, you should take the following into consideration:

l           Take effective measures to protect the power supply system against the power grid interference.

l           Separate the protection ground (PGND) of the switch from the grounding device or lightning protection grounding device of the power supply equipment as far as possible.

l           Keep the switch far away from radio stations, radar, and high-frequency devices working in high currents. If necessary, adopt electromagnetic shielding.

3.2.4  Grounding Requirements

A good grounding system is the basis for a switch to work stably and reliably and the important guarantee of lightning protection, anti-interference and ESD. You should provide a good grounding system for the switch.

3.2.5  Power Supply Requirements

The S7500 series adopt N+1 power supply redundancy (N is 1 or 2).

1)         AC power module parameters:

l           Rated voltage range: 100 to 240 VAC, 50/60Hz

l           Input voltage range: 90 to 264 VAC, 50/60Hz

l           Maximum output power: 450 W

2)         DC power module parameters:

l           Rated voltage range: –48 to –60 VDC

l           Input voltage range: –36 to –72 VDC

l           Maximum output power: 450 W

3.3  Installation Planning

Since the S7500 series are a kind of complex equipment, it is necessary to make a good plan and arrangement concerning installation position, networking mode, power supply and cabling before installation.

3.3.1  Installation Space Requirement

For better heat dissipation and equipment maintenance, it is recommended that the front and back of the switch should be at least 1 m (39.4 in.) away from walls or other devices, and that the left and right side should be at least 0.8 m (31.5 in.) away from walls. If the switch is to be installed in a cabinet, the headroom in the equipment room should be 3 m (9.84 ft.) at least.

3.3.2  Cabinet-Mounting Requirements

Before mounting the switch in a cabinet, make sure the cabinet meets the following requirements:

l           Mount the switch in an open cabinet if possible. However, if you mount a switch in a closed cabinet, make sure that the cabinet is equipped with a good heat dissipation system.

l           Make sure that the cabinet is steady enough to support the switch and accessories.

l           Make sure that the cabinet fits the switch size, and that there is clearance around the left and right panels of the switch for heat dissipation.

3.4  Installation Tools

Table 3-4 List of required installation tools

Type		Tools
General tools	Measuring and marking tools	Long tape, ruler (1 meter long), gradienter, marking pen, powder marker, and pencil
	Drilling tools	Percussion drill, drill bits, and vacuum cleaner
	Fastening tools	l      Flat-blade screwdriver P4-75 mm l      Phillips screwdrivers P1-100 mm, P2-150 mm and P3-250 mm l      Socket wrench M5 l      Box-end wrench M6 l      Double box-end wrench (10×12) or double open-end wrench (10×12)
	Small tools	Sharp-nose pliers, diagonal pliers, vices, hand-held electric drill, file, handsaw, crowbar and rubber hammer
	Auxiliary tools	Hair brush, tweezers, paper knife, hand bellows, electric iron, solder wire, fork and ladder
Special tools	ESD-preventive wrist strap, cable stripper, crimping pliers, RJ-45 crimping pliers and wire punchdown tool
Tools for cleaning optical fibers	Airlaid paper and fiberscope
Meters	Multimeter, 500 V Meg-ohmmeter (used to measure the insulation resistance), bit error ratio (BER) tester, optical power meter and earth resistance tester