Doc# 1231558 • REV C (November 2017) Page 5 of 20
NOTE: When specifying units with 2g reset coil holding
strength simultaneously with a 24 VDC reset coil, do not install
the switch with a horizontal orientaon or upside down. The
reset coil lacks sucient holding force for anything other than
a vercal “face up” orientaon (Figure 4B).
2.1 Maintenance Convenience Versus Measurement Quality
While it is desirable to mount the switch in a locaon in which it can be easily serviced and
maintained, this should not be the dominant consideraon. The switch serves as a me-
chanical sensor and for it to provide suitable machinery protecon, it must be mounted in a
locaon and orientaon where the machine’s ineral forces during malfuncon condions
will be suitably large to trip the switch. Thus, locang the switch for opmal mechanical
sensing – rather than opmal serviceability – must always remain the primary consideraon.
However, in most circumstances, judicious choice of mounng locaon and switch orienta-
on can accommodate both requirements sasfactorily.
2.2 Sensive Axis
The switch is designed to respond to ineral forces only in the direcon of its sensive axis
(Figure 4). When care is not taken to mount the switch properly, relavely large ineral
forces can occur elsewhere on the machine that will not be transmied properly to the
switch, and/or will occur in a direcon perpendicular to the switch’s sensive axis. Both of
these condions can render the switch’s ability to trip less eecve or even ineecve.
2.3 Horizontal Orientaon
A horizontal orientaon of the switch means that it is mounted with its sensive axis per-
pendicular to the direcon of gravity (refer to Figure 4A). In this orientaon, the eects of
gravity on the switch’s trip mechanism are negligible and the trip point is governed almost
enrely by the spring. It is recommended that the switch be oriented horizontally because
most machines are less constrained (less s) in the horizontal direcon than in the vercal
direcon and will therefore vibrate more in the horizontal direcon.
2.4 Vercal Orientaon
A vercal orientaon of the switch means that it is mounted with its sensive axis parallel to
the direcon of gravity. It is not recommended that the switch be oriented vercally (except
as noted above) because most machines are more constrained (more s) in the vercal di-
recon than in the horizontal direcon, and will therefore vibrate less in the vercal direcon.
2.5 Horizontal Machines
Although Figures 5 and 6 both show horizontal switch orientaons, they are not equivalent.
In Figure 5, the sensive axis of the switch points directly at the machine’s sha; in Figure
6, it does not and instead is aimed at point P somewhere above the sha. Either mounng
orientaon can be eecve, but 5 is preferred.
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