NIVELCO NIVOROTA EL-EK-7 Series User Manual

Thank you for choosing NIVELCO instruments.
We are convinced that you will be satisfied with our product.

1. INTRODUCTION

The new NIVOROTA E-700/800 rotary paddle level switches of the well-known NIVELCO design can be
used for detecting the level of lumpy materials, powders, and granules. Mounted onto tanks, silos, and
hoppers, they monitor and control the level, filling, and emptying of stored materials such as stones, fly ash,
sand, coal, feed, beet slices, etc.
A low-power electric motor drives the paddle, which rotates freely in the absence of the material. Its rotation
in the EK / EH is mono-directional; in the
paddle, the output contact switches from NC state to NO state, and the motor is turned off. When the material
level drops, the paddle runs free again, the motor is reactivated, and the switch returns to its original state
(NC). In the case of low-level detection, the material usually covers the blade, with the output contact staying
in NO state, and the motor stopped. When the material drops to a level where the paddle can rotate freely
again, the motor restarts and the control switch returns to the NC position.
The process connection can be threaded (1" or 1½" BSPT) or a mounting plate. It is recommended to use
adapters for threaded connection points other than the standard version. The mounting plate can be attached
to the unit with a threaded process connection. Mounting nuts are available for mounting onto a bracket,
depending on the size of the process connection. A suitable paddle must be chosen for every particular
medium density. The single-blade paddle is recommended for higher density materials and granular solids,
while the 3-blade paddle is recommended for lower density materials, powders, and solids. The 1-blade
paddle or 2-blade paddle with flexible coupling can also be used with a suitable threaded connection, while
the 3-blade paddles can only be installed using a mounting plate.
If the standard version's insertion length is not enough, there are rod or cable extension types available,
depending on the application. For light materials with moderate stress, the solution is to use (Ø10) pipe
extension. The device's shaft must be protected against being hit by falling stones or other coarse materials
by using a flexible coupling. If the insertion length is customized for any technical reason, the rod-extended
design with an adjusting unit is recommended. This can be ordered separately. In the case of a cable
version, if the desired length falls between two available sizes, the desired length can be achieved by cutting
the cable to the appropriate size. The counterweight stretches the cable to avoid the paddle climbing up onto
the medium surface. If additional stiffening of the cable probe is required, a rigid pipe can be ordered as an
accessory.
Caution! If the pipe is cut to size, at least 30 mm (1.2 inches) must be left free between its top end and
the cable rope assembly connector.
If the medium temperature exceeds 120 °C (248 °F), a high-temperature version must be used, equipped
with a heat sink, raised from the process connection, and only available with aluminum housing.
Dust-Ex versions are available for use in hazardous environments.

2. TECHNICAL DATA

2.1 G
ENERAL DATA
Version
Insertion length (L)
Number and material of the
blades
Rotation speed
Material of wetted parts
Medium density (guideline value)
Medium temperature
Ambient temperature
Relative humidity
Process pressure
Output
Paddle-rotation / shutdown
indication
Power supply
Process connection
Power consumption
Electrical connection
Electrical protection
Ingress protection
Housing material
Weight
A EK  / EH  –  –4M, –8M use 24 V DC (-15%...+10%)
(1)
Z
The connection between the device housing and the process connection is rigid, it cannot be turned or twisted!
EL / EM, it is bidirectional. When the medium reaches the
Standard
EL– / EK–7
Standard: 200 mm (7.85 inches) – Rod extension: 0.3...3 m (1...10 ft)
1.4571 (316Ti) Stainless Steel, Material of the seal: NBR
-20...+120 °C (-4...+248 °F)
Nominal value: 230 V AC (50/60 Hz) +10% -15%, 120 V AC (50/60 Hz) +10% -15%
2x M20x1.5 plastic cable glands, for Ø6...Ø12 mm (Ø0.25...Ø0.5 inches) cable
2x terminal blocks for 0.5...1.5 mm
Powder-coated aluminum
Standard: 1.6 kg (3.52 lb), Rod-extended: 1.6 kg (3.52 lb) + extension 1.6 kg/m (1 lb/ft),
Cable-extended: 2.6 kg (5.73 lb) + extension 1.4 kg/m (0.94 lb/ft), counterweight: 1 kg (2.2 lb)
EL– / EK–8
Cable extension: 1...3 m (3.3...10 ft)
1.4571 (316Ti) / 1, 2, 3; as per order code
~1 rpm (@50 Hz)
min. 0.1 kg/dm
3
-20...+80 °C (-4...+176 °F)
Ex variant: see 2.2 Explosion protection data
-30...+60 °C (-22 °F ... +140 °F)
max. 90%
max. 3 bar (0.3 MPa, 43.5 psig)
SPDT 250 V AC, 6 A, AC1
Two-toned (green/red) LED
24 V AC (50/60 Hz) +10% -15%, 24 V DC (18...28 V DC)
1" BSPT; 1½" BSPT; mounting plate
(BSPT thread can also be screwed into BSP or NPT thread)
max. 4 VA (4 W)
2x internally threaded ½" NPT connection for protective pipes
(AWG20...AWG15) wire cross section
2
Class I.
IP67
Plastic (PBT)
High-temperature
EM– / EH–7
1.4571 (316Ti) Stainless Steel, Material of the seal: FPM
-20...+200 °C (-4...+392 °F)
(1)
Powder-coated aluminum

eka7021a0600h_07 1 / 5