R&M Materials Handling, Inc
STAGEMAKER
®
Concert Hoist
Springfield, Ohio USA
Technical Guide
:
800 955-9967
June 2009
www.rmhoist.com
RM-STGMKR-TG-2002-6-ENG.doc
49
®
13 Hoist Limit Switch
13.1 Upper and Lower Electrical Limit Switches
Upper and lower electrical limit switches are for over-travel protection and available for all models except
the SM2. The limit switches are load block or chain-stop activated.
The upper and lower electrical limit
switches are effective only when the hoist is mounted in the normal position of a fixed installation.
The
switch housing is recessed into the underside of the hoist body.
Note: The upper and lower electrical limit switches are not to be used as automatic stops during normal
operation of the hoists.
The hook block activates the upper limit switch as it approaches the hoist body and once it is activated,
only the “up” circuit is opened. When the hook block is lowered to its lowest limit of travel, the chain-stop,
mounted to the free end of the load chain, activates the lower limit switch, which opens the “down” circuit
only.
As standard the lower limit position only is adjustable from maximum lift. It is adjusted by repositioning the
chain-stop on the free end of the load chain. The chain-stop shall always be located at least 36 inches
[1m] from the end of the chain. If the load block has to stay a certain distance away from the hoist body,
an extra chain-stop has to be mounted to the load chain between hoist body and the load block. The extra
chain-stop strikes the limit switch instead of the load block. This extra chain-stop is only possible for one-
fall units. In all other cases, use a geared limit switch. See Hoist Limit Switches.
13.2 Geared Limit Switch
A geared limit switch allows the user flexibility to adjust and set the limits of hoist travel. The switches are
wired into the control circuits. The limit switch enclosure has a protection rating of IP-55.
Note: The Geared Limit Switch is not designed as a precision limit switch and should be used as a safety
stop only. The geared limit switch accuracy is dependent on the hoist selected and the height of lift
(accurate to /- 15"). The use of contact type upper and lower limit switches described above in
section 13.1 (only when the hoist is mounted in the normal position) or the Stagemaker Configuration C is
recommended when the application requires close tolerance positioning.
Once the limit switch is tripped, the load must travel at least 18 inches [50cm] in the opposite direction to
reset the switch.
The 2-switch geared limit switch is adjustable and provides over-travel protection for the upper and lower
limits of hoist travel. The 4-switch geared limit switch provides over-travel protection for upper and lower
limits of hoist travel and it can be set for two additional intermediary positions as needed.
Configuration 2 switches
4 switches
A
Not available
Not available
B
Optional for all SM hoists (except SM2)
Optional for SM5 and SM10 only.
C
Optional for all SM hoists
Optional for SM5 and SM10 only.
D
Must use a 4-switch geared limit
Standard
E
Optional for all SM hoists
Optional for SM5 and SM10
S
Not available
Not available
V Optional
Optional
When the rotary limit switch is installed on the outside of the hoist body, it increases some of the outline
dimensions of the hoist body.
