Dwyer Ultra-Mag™ - Manual

Series P/G Explosion Proof Ultra Mag™ Level Switches
Specifications - Installation and Operating Instructions
Bulletin 407
Driving
Magnet
Driven
Magnet
Sealed
Junction Box
Epoxy Seal
Sealed
Switch Cavity
DIAPHRAGM
ADJUSTMENT
SWITCH
ADJUSTMENT SPRING
SWITCH
ADJUSTMENT
SCREW
The Series P/G Ultra Mag™ Level Switch provides level indication by detecting
pressure applied by the bulk material to the sensing diaphragm. The switch is
tripped magnetically, as the result of 2 magnets with like poles repelling one
another. The fields of the magnets perform through the nonferrous wall of the
switch housing. Pins, links and “O” rings, which often cause failure due to moisture,
dirt, and corrosion, are eliminated. The switch enclosure is completely sealed.
The unit performs as follows:
1. When the diaphragm is forced inward by the product bulk material, the
“driving” magnet moves inward, as does its magnetic field.
2. The field of the “driving” magnet repels the field of the “driven” magnet
attached to the switch arm, and the switch is tripped.
3. Deactivation occurs when product is removed from the vessel and the
diaphragm and “driving” magnet returns to their original positions.
SENSITIVITY ADJUSTMENT
The P/G Ultra Mag™ offers a sensitivity adjustment that is accessible from outside
of the bin and easily adjusted with a screwdriver. This enables the user to adjust
the sensitivity of the unit, should vessel contents change, without removing the unit
from the vessel. Turning the adjustment screw inward increases operating forces,
and turning the screw outward decreases operating forces. A maximum of 4 turns
is available. When the screw is bottomed, the force is at a maximum. With 4 turns
out the diaphragm force is at a minimum. Normal setting is two turns out. See
Figure 1.
SWITCH ADJUSTMENT
The switch adjustment determines whether actuation occurs early in diaphragm
travel or late. Turning the screw inward retards action and causes the switch to trip
late. Backing the screw out results in early actuation when the diaphragm is slightly
depressed. A center switching position is desirable.
Regardless of the position (angle) in which the control is eventually mounted, the
switch should trip at mid travel of the diaphragm. “Break” (switch off) should never
occur within the last 1/4 of travel outward. “Make” (switch on) should not occur after
3/4 travel inward.
MOUNTING
A choice of either suspension or flange mounting is available to match your
application. Flange mounting is the best choice for control of low or intermediate
level in vessels containing granular product that does not “bridge”, “rathole”, or
otherwise build up on vessel walls. Choose suspension mounting for high level in
vessels and for better operation with “bridging” product. Note that the mounting
configuration is represented by the letter “S” for suspension or “F” for flange.
SPECIFICATIONS
Service: Compatible powder or bulk solids.
Wetted Materials:
Mounting Flange: Aluminum or 304 SS.
Diaphragm: Urethane, Buna-N, PTFE, Silicone Rubber,
Polyester, Fluoroelastomer, White Buna-N (food grade), or EPDM.
Temperature Limits: Depends on diaphragm material.
Standard switch: -40 to 185°F (-40 to 85°C), high temperature switch: -40 to
350°F (-40 to 176°C).
Pressure Limit: 60 psig (4.14 bar).
Enclosure Rating: General purpose or weatherproof and explosion-proof.
Electrical Connections: 18 gage solid core, 600 volt TEW 105°C, style 1015.
Epoxy sealed at conduit entrance. 12˝ (304.8 mm) long.
Conduit Connection: 1/2˝ female NPT.
Process Connection: For flanged models standard is 8-3/8˝ (212.725 mm)
diameter bolt hole circle.
Mounting Orientation: Flange mount or suspend depending on model.
Set Point Adjustment: Internal screw.
Weight: 7 lb (3.18 kg).
Options: Suspension kits and flange adaptor rings.
Agency Approvals: UL and CSA.
PROXIMITY CONTROLS
Phone: 219/879-8000 www.dwyer-inst.com
A DIVISION OF DWYER INSTRUMENTS, INC. Fax: 219/872-9057 e-mail: [email protected]
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A.
WIRING
The P/G Ultra Mag™ has a 1/2˝ NPT conduit connection. Remove the back plate
to access the single pole double throw snap-switch. The switch rating is: 15A @
125, 250, or 480 VAC. There are three terminals on the snap-switch: “Common”,
“Normally Open”, and “Normally Closed”.
ELECTRICAL
CONNECTIONS
(REAR VIEW)
NTS
NORMALLY
CLOSED
NORMALLY
OPEN
COMMON
ELECTRICAL RATING
15 AMPS @ 125, 250, OR 480 VAC
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