Banner SC22-3E Safety Controller with Ethernet - Manual (Page 101)

The installation of the hand controls must consider:
• Failure modes that would result in a short circuit, a broken spring(s), mechanical seizure, etc. that would result in not detecting the
release of a hand control
• Severe contamination or other environmental influences that may cause slow response when released or false ON condition of the
hand control(s), e.g., sticking of a mechanical linkage
• Protection from accidental or unintended operation (e.g., mounting position, rings, guards or shields)
• Minimizing the possibility of defeat (e.g., hand controls must be far enough apart so that they cannot be operated by the use of one
arm — typically, not less than 550 mm (21.7") in a straight line, per ISO 13851
• The functional reliability and installation of external logic devices
• Proper electrical installation per NEC and NFPA79 or IEC 60204
When used in single-cycle or single-stroke mode, the machine control must provide an anti-repeat feature so that the operator must
release the two-hand control actuators after each machine cycle, before a new cycle can be initiated. In addition to the anti-repeat of the
machine control, the Safety Controller input(s) can also be used to halt a machine cycle and help in providing Anti-Repeat Control (see
Caution below).
CAUTION: . . . Install Hand Controls to Prevent Accidental Actuation
Total protection for the two-hand control system from “defeat” is not possible. However, the user is required by OSHA reg-
ulations to arrange and protect hand controls to minimize possibility of defeat or accidental actuation.
CAUTION: . . . Machine Control Must Provide Anti-Repeat Control
Appropriate anti-repeat control must be provided by the machine control and is required by U.S. and International
standards for single-stroke or single-cycle machines.
10.5.1 Two-Hand Control Separation (Safety) Distance
Both hand controls must be located far enough away from the nearest hazard point that the operator cannot reach the hazard with a hand
or other body part before the hazardous motion ceases. This is the “separation distance” (“safety distance”), and may be calculated as
follows.
WARNING: . . . Location of Touch Button Controls
Hand controls must be mounted a safe distance from moving machine parts, as determined by the appropriate
standard. It must not be possible for the operator or other non-qualified persons to relocate them. Failure to establish and
maintain the required safety distance could result in serious injury or death. so that the machine’s safety-related
control system interrupts the circuit to the machine primary control element(s), resulting in a non-hazardous condi-
tion.
Formulas for U.S. Installations Formula for EU-Certified Installations
For Part-Revolution Clutch Machinery where the machine and its
controls allow the machine to stop motion during the hazardous portion
of the machine cycle, use the following formula:
Ds = K x (Ts + Tr + Th)
The formula used to calculate the minimum safety distance
(S) from the nearest actuator to the danger zone is:
S = (K x T) + C
For Full-Revolution Clutch Machinery where the machine and its
controls are designed to complete a full machine cycle, once activated,
use the following formula:
Ds = K x (Tm + Tr + Th)
In all cases, where:
SC22-3/-3E Safety Controller Instruction Manual
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