NonStop S-Series Planning and Configuration Guide (G06.29+)

Site Planning and Preparation
HP NonStop S-Series Planning and Configuration Guide—523303-021
12-12
Electrostatic Discharge (ESD) Control and
Protection
When the EPO contacts are open, there is 56 V DC across them. The contacts should
be rated at a minimum of 75 V. When the EPO switch closes (the switch shorts out the
pins on the EPO connector on the system enclosure) there is a 5 mA current for each
enclosure connected to the switch. A single pair of contacts rated at 200 mA can
support a 16-enclosure system. If you want to use separate contacts for each
enclosure, the contacts should be rated at 20 mA.
EPO Wiring Diagram for a Typical Two-Enclosure System
Electrostatic Discharge (ESD) Control and Protection
HP highly recommends that when you replace a system component, you wear a
properly grounded wriststrap with an in-series resistor to protect the component from
damage caused by electrostatic discharge (ESD).
In dry environments or in rooms containing materials likely to generate static electricity,
HP recommends that electrostatic protection (antistatic) mats be placed in front of and
behind each enclosure.
VST199.vsd
Neutral Bus
Feeder Breaker with
Shunt-Trip Coil
Mains AC
Power Panel
Normally-Open
Contacts
AC Power
Cables
1234
Enclosure 1 Enclosure 2
EPO 1
2
EPO 2
2
20 A
2
Junction
Box
EPO Cables
To Enclosure 1
To Enclosure 2