Safety Light Curtain Systems Owner's manual

46 P/N 68413 rev. A
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: [phone]
EZ-SCREEN Point
Instruction Manual
Troubleshooting and Maintenance
5.2 Electrical and Optical Noise
The EZ-SCREEN System is designed and manufactured to be
highly resistant to electrical and optical noise and to operate
reliably in industrial settings. However, serious electrical and/or
optical noise may cause a random trip or latch condition. In very
extreme electrical noise cases, a lockout is possible. In order
to minimize the effects of transitory noise, the EZ-SCREEN
System will respond to noise only if the noise is detected on
multiple consecutive scans.
If random nuisance trips occur, check the following:
• Poor connection between the sensor and earth ground;
• Optical interference from adjacent light grids or other
photoelectrics; or
• Sensor input or output wires routed too close to “noisy”
wiring.
Checking for sources of electrical noise: It is very important
that the EZ-SCREEN Point sensors have a good earth ground.
Without this, the system can act like an antenna and random
trips and lockouts can occur.
All EZ-SCREEN System wiring is low voltage; running these
wires alongside power wires, motor/servo wires, or other high-
voltage wiring, can inject noise into the EZ-SCREEN system. It
is good wiring practice (and may be required by code) to isolate
EZ-SCREEN System wires from high-voltage wires.
The Banner BT-1 Beam Tracker is a very good tool for detecting
electrical noise. It can be used to detect electrical transient
spikes and surges. Cover the lens of the BT-1 with electrical
tape to block optical light from getting into the receiver lens.
Press the “RCV” button on the BT-1 and position the Beam
Tracker on the wires going to the EZ-SCREEN or any other
nearby wires. Noise caused by the switching of inductive loads
should be addressed by installing proper transient suppression
across the load.
Checking for sources of optical noise: Turn off the emitter,
completely block the emitter beam, or open the Test input,
then use a Banner BT-1 Beam Tracker to check for light at
the receiver. Press the “RCV” button on the BT-1 and move it
across the full length of the receiver’s sensing window. If the
BT-1’s indicator lights, check for light from other sources (other
safety light screens, grids or points, or standard photoelectric
sensors) by “tracking down” the emitted light from them.
WARNING . . . Shut Down
Machinery before Servicing
The machinery connected to the EZ-SCREEN
System must not be operating at any time during this
procedure. Some servicing procedures may involve working close
to the hazardous areas of the guarded machine.
Serious bodily injury or death could result.
CAUTION . . . Electrical Danger
Exercise care whenever troubleshooting,
repairing, or modifying the EZ-SCREEN System
and/or the machine control system. Always disconnect all
power from the EZ-SCREEN System and the guarded machine
before making any wire connections or before replacing any
component.
Electrical connections or repairs should be done only by a
Qualified Person (see Safety Glossary).
WARNING . . . Power Failures and
Lockouts
A lockout is a definite indication of a problem
and should be investigated at once, by a Qualified Person.
Attempts to continue to operate machinery by bypassing the
EZ-SCREEN System are dangerous and could result in serious
bodily injury or death.