3. Use pipe of sufficient size and strength to support the
control. Provide a hanger or stand to help support the
weight of the cage if necessary.
4. All piping should be straight and free of low spots or pockets.
Lower liquid line should drain toward vessel and upper line
toward control.
5. Shut-off valves are recommended for installation between
the vessel and the cage assembly.
6. Once external cage is mounted, install TUFFY II into cage
per Section 1.3.1 or Section 1.3.2 on page 5.
Caution:
Operation of all buoyancy type level devices should be done
in such a way as to minimize the action of dynamic forces on
the float or displacer sensing element. Good practice for
reducing the likelihood of damage to the control is to equal-
ize pressure across the device very slowly.
1.4
Wiring
NOTE: A switch or circuit breaker shall be installed in close proximity
to equipment and within easy reach of operator. It shall be
marked as the disconnecting device for the equipment.
NOTE: For supply connections in installations with ambient tempera-
ture up to +158° F (+70° C), use wire with a minimum rating of
+167° F (+75° C), as required by process conditions.
Installations with ambient temperatures up to +176° F (+80° C)
require wire with a minimum rating of +185° F (+85° C) as
required by the process conditions. Use a minimum of 14 AWG
wire for power and ground field wires.
On high temperature applications above +250° F (+120° C)
process temperature, a suitable heat resistant covered wire
should be used between the TUFFY II and the first junction
box located in a cooler area. On non-hazardous applications,
flexible conduit may be used between TUFFY II and the first
junction box. Conduit should have sufficient slack to permit
removal of the switch assembly.
1. Unscrew and remove switch cover.
2. Pull in supply wires and connect to the proper terminals,
Figure 5, 6, 7
&
8
. Please note that some switches are
reverse acting. Be sure to connect to proper terminals
according to wiring diagrams.
NOTE: Ensure that excess wire does not interfere with replacement of
the switch cover or movement of the switch mechanism.
NOTE: The ground screw (green head) is located to the right of the
switch. Housing must be grounded via protective ground screw
in base of housing. Hazardous locations require a conduit seal
within 18" (457 mm) of the conduit connection, and the conduit
must be screwed into the housing a minimum of 5 times.
44-607 Tuffy
®
II Liquid Level Switch
7
