User Manual

SAFETY
Safety handbook page - 13 -
PNSPO
According to EN 60204-1 the requirements for an emergency stop function are
• it shall override all other functions and operations in all modes
• power to the machine that can cause a hazardous condition(s) shall be remove as
quick as possible without creating other hazards
• reset shall not initiate a restart
The standard divides applications into different stop categories. The choice of the
category is depending on the risk assessment of the machine.
• Stop category 0: stopping by immediate removal of power to the machine
• Stop category 1: a controlled stop with power available to the machine actuators to
achieve the stop and the removal of power when the stop is achieved
• Stop category 2: a controlled stop with power left available to the machine
actuators
Especially Stop category 2 is very risky and therefore EN 1037 prevention of
unexpected start-up has to be considered. Hazards other than mechanically generated
by movable elements such as laser beam also need to be taken into account.
If persons are present in dangerous zones e.g. for maintenance, devices for isolation
and energy dissipation have to be used. Latent energy can be stored in mechanical
parts continuing to move via inertia, mechanical parts liable to move by gravity,
capacitors, accumulators, pressurised fluids or springs.
4.3 Schematics
Below you will find some e-stop application examples sorted by safety category
according EN 954-1 starting by category 1. OMRON offers different series of safety
relay units as G9SA and G9SB.
4.3.1 Single channel input, category 1
Products: G9SA-301, A22E
- 1-channel configuration
- category 1
- manual reset
S1: E-Stop pushbutton A22E
S2: Reset Button
KM1/KM2: Contactor
M: 3 phase motor