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Relay conforms to standards
EN 574section III C and
EN 60204-1 (1998) |
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2 positively-driven NO contacts |
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Up to 230V supply voltage |
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Dual channel activation |
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Crossfault monitoring |
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Optional with removable terminals |
Two-hand relays are used to provide operator safety on power
presses and punches. Both hands must be used to activate the machine, thus
ensuring that the operator is outside the danger zone during the dangerous
closing operation. All equipment used for two-hand operation must conform
to the applicable standards and regulations (see overleaf).
The ZH 1/456 regulations require that the
distance between the control switches and the components executing the
dangerous closing movement must properly determined and strictly maintained.
It is very important that the distance between the control switches of
the two-hand switch and the danger zone is adequate to ensure full safety.
If the operator releases even one of the switch elements of the two-hand
switch the dangerous closing movement must be either interrupted or completed
before the operator can reach the danger zone. Standard
prEN999 provides the following general formula for calculation of the
minimum safety distance:
S=K x T+C
S: Minimum safety distance (mm) measured from the danger zone
to the reference point, reference line or protection area
K: Constant (mm/s) derived from data on the approach speed of
the body or body parts
T: Aggregate response time (s)
C: Additional distance (mm) based on the penetration into the
danger zone before activation.
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