Manual

Model VRLS Vibrating Rod Level Switch
Specifications - Installation and Operating Instructions
Bulletin L-VRLS
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]
SPECIFICATIONS
Service: Dry powder or bulk materials compatible with wetted materials.
Sensitivity: Min. bulk density of 20 lb/ft
3
(320 kg/m
3
).
W
etted Materials: 304 SS.
T
emperature Limits:
A
mbient: -40 to 140°F (-40 to 60°C);
Process: -40 to 176°F (-40 to 80°C).
Pressure Limit: 150 psi (10 bar).
Power Requirement: 20 to 250 VAC/VDC, 50/60 Hz.
Power Consumption: 15 VA.
E
nclosure: Aluminum, painted.
Enclosure Rating: IP65.
Switch Type: SPDT.
Electrical Rating: 5 A @ 250 VAC.
Electrical Connections: Screw terminals.
Conduit Connection: 1/2˝ female NPT x 2.
Process Connection: 1˝ male NPT.
Indication Lights: Internal: green and red LED.
Sensing Delay: 0 to 6 s.
Weight: 4.4 lb (2.0 kg).
T
he Model VRLS Vibrating Rod Level Switch is an economical choice in level
d
etection of powders and bulk solids. Ideal for silo or hopper applications, its probe
d
esign allows for self-cleaning, ensuring no build-up of material and accurate
detection. Sensitivity is adjustable for detection ranging from large granular
material to small powders with low bulk densities.
O
perating Principle
T
he vibrating probe level switch is a system kept in resonance by piezoelectric
e
lements. When the vibration of the probe is damped by the surrounding medium,
the change in resonant frequency is detected by an electronic unit and converted
into a digital switching signal. Sensitivity adjustment for different detected materials
is not frequent, as there is no additional circuitry for signal amplification.
Electrical Connections
Terminal Functions
• L+, N-: Power
• NC, COM, NO: Relay Output
• Ground Connection
Panel Functions
-PWR: Power
-SIGNAL: Output Signal
-FSH (Fail Safe High): After power is connected, signal indicator lamp will turn on
and the switch will close. When probe detects material, the signal indicator lamp
will turn off and the switch will open.
-FSL (Fail Safe Low): After power is connected, the signal indicator lamp will turn
off and the switch will remain open. When probe detects material, the signal
indicator lamp will turn on and the switch will close.
4
-9/32
[
108.83]
4
-29/64
[
113.03]
1˝ NPT
5
1/64
[
20.19]
10-27/32˝
[275.35]
Ø
3/4
[
18.87]
Electrical Connection
s
Terminal Fu
nctions:
• L+, N-
:
Power
•
NC,
COM, NO: Relay Output
•
Ground
Connection