Flowserve SMB Series Electric Actuators - Manual (Page 18)

SMB Series/SB Series Installation and Maintenance FCD LMENIM1401-04-AQ – 01/15
18
4.4.2 Four-Train Geared Limit Switch
The rotor-type, four-train geared limit switch employs four rotary drum switches. Each rotary drum
switch contains four contacts. When the rotor is properly set to trip at the desired position, two of
these contacts open electric circuits and two of the contacts close electric circuits. One rotor is set
to trip at the full open position of the valve, and one rotor is set to trip at the full close position of the
valve. The other two rotors are set at some intermediate position depending on the application.
For the geared limit switches to trip at any desired position, follow the steps in Section 4.4.1,
Two-Train Geared Limit Switch, with the exception that the piece numbers refer to Figure 4.3 and
Table 4.5.
NOTE: The upper Set Rod (piece #48) allows adjustment of the two adjacent upper rotors, and the
lower Set Rod (piece #48) allows adjustment of the two adjacent lower rotors.
Figure 4.3 – Four-Train Geared Limit Switch – Rotor Type
25 26 21 28 27 35 34 30 29
46 43 53 41 54 48 61
22 23 26 24 31
32
55
52
44
58
45 42 68
69
71
57 47 50 49
01-472-0007-3 01-472-0007-3