The LVD-800 Series fail-safe bin monitor is the state-of-the-art in rotary paddle technology. Utilizing
magnetic sensing technology and a unique housing design, the LVD-800 Series fail-safe bin monitor is the
most reliable, technician-friendly, rugged and economical truly fail-safe rotary paddle point level
control sensor of its kind.
The LVD-800 Series fail-safe bin monitor provides the ultimate in performance wherever critical
continuous operation must be ensured. Detection of both material presence and its own operational
status is performed on a continuous basis. The LVD-800 Series fail-safe level sensor monitors its
electrical and mechanical operating condition. This, in conjunction with separate outputs provided
for material sense and unit status (fault conditions) makes this unit a "truly" fail-safe device.
While the LVD-800 Series fail-safe bin monitor is an evolution in rotary paddle technology, it continues
to use tried-and-true operating techniques. Unlike many other available units, the LVD-800 Series
incorporates a feature that automatically shuts off its motor when the paddle is in a stalled condition.
This extends the life of the unit and minimizes maintenance.
Principle of Operation
The operation of the LVD-800 Series rotary paddle fail-safe bin monitor uses magnetic sensing
technology to detect both material presence and operational status of the unit. This method is simple
and more reliable than that used by other manufacturers. The unit is installed through the wall of the
vessel so that the paddle protrudes inside the vessel. A small electric motor drives the paddle,
which rotates freely in the absence of material.
The rotation of the unit’s shaft is continuously monitored by detection of a magnetized rotating disk
(patented). When the paddle is impeded by material, the shaft rotation stops. The motor rotates within
the housing and magnetized sections of the motor mounting plate are detected (patented). Use of these
magnetic sensing techniques eliminates problems that may occur with fouling of the optical systems used
by other brands.
The built-in microcontroller performs self-diagnostics and monitors both shaft and motor mounting plate
rotation. This allows the unit to easily distinguish between material presence and any electrical and
mechanical failure of the unit. When material presence is detected, the SENSE relay changes state and
the drive motor is deenergized to extend motor life. This output is available to control a process
function or alarm circuit. When the material level drops, a tension spring returns the drive motor to
its original running condition and is reactivated.
A unit failure is detected by sensing a lack of shaft rotation while material presence has not been
detected by rotation of the motor mounting plate. In a failure condition the independent FAULT
relay will change state indicating that an error condition exists. Monitoring the state of both the
SENSE and FAULT relays provides the most flexibility for control and fail-safe monitoring.
The rugged and reliable design of the LVD-800 Series fail-safe bin monitor makes it the best choice for
critical level control applications. The unit is compatible with many granular, pelletized and powder
bulk applications. It can be utilized for high level indication of materials over 160 kg/m³
(10 lb/ft³) and for low and intermediate level indication for materials over
80 kg/m³ (5 lb/ft³). The LVD-800 Series bin level monitor can be installed almost
anywhere dry bulk materials are stored including bins, hoppers, silos and tanks.
SPECIFICATIONS Power Requirements: 115 Vac (±15%); 9 VA; 50/60 Hz; 230 Vac (±15%); 9 VA; 50/60 Hz Ambient Operating Temp: -40 to 65°C (-40 to 150°F) Internal Bin Temp*: Standard Unit: to 121°C (250°F) Hi-Temp Unit: to 399°C (750°F) Conduit Connection: Two (2) ¾ NPT
Material Sense: One SPDT; 5A @ 250 Vac, 30 Vdc max Unit Status (Fault): One SPDT; 5A @ 250 Vac, 30 Vdc max Maximum Pressure: 30 psi (2 bar) Sensitivity: 80 kg/m³ (5 lb/ft³) minimum material density (when using
large 3-vane paddle) Indicators: Red and green high intensity LEDs indicate material sense and unit status conditions
(Ordinary Location unit only) Housing: Die cast aluminum, NEMA-4, IP66 Housing Finish: Powder coating Mounting Connection: 1¼ NPT Weight: Approx. 3.9 kg (8.5 lb)
MATERIALS OF CONSTRUCTION/ACCESSORIES
Flexible Couplings: 304 stainless steel Mounting Plates: Carbon steel or 304 stainless steel All Paddles Except Ex-Flex: 304 SS Ex-Flex Belt: 304 SS coupling, rubber/fabric blend belt Flexible Cable Extension: 304SS ¼" diameter
LISTINGS/APPROVALS Hazardous Locations: Class I, Div. Groups C, D; Class II, Div. 1 & 2, Groups E, F, G, CE Mark
† All amounts shown in USD Note: Comes complete with operator’s manual.
* Order paddles separately.
For optional 24VDC, add suffix "-24V" to model number, (available on the LVD-803 only), add $30 to price.
For optional high temperature version up to 750°F for SS (top or vertical mount only), add suffix "-HT" to model number, add $300 to price.
* Insertable paddles eliminate the need for mounting plate. LVD-800-1VS is insertable through either a half or full 11/4" coupling, that is welded to the bin wall. LVD-800-1V is insertable through a half 11/4" coupling.
* Shaft guards are required for use with solid shaft extensions to limit the movement caused by side loading that would otherwise damage the working components of the paddle unit. Shaft guards should be the same length as the extension and should always be used when the extension meets or exceeds 460 mm (18") in length.
** Extension and guard lengths [not to exceed 3.6 m (144") in length]
Ordering Example: (1) LVD-800-3V 3 Vane standard for average weight [>320 kg/m3 (>20 lb/ft3)] materials, USD32.00 plus (1) LVD-803 Dry level switch, 115 Vac, 11/4, USD400.00, USD32.00 + 400.00 = USD432.00
LVD-800 Series - Dry Material Rotary Paddle Level Switches