Barksdale UNS2000 Multi Level Float Switch up to 3000 mm

A configurable float switch with up to six switch points on one stem

The Barksdale UNS2000 is a vertical multi-level float switch that can carry up to six reed-contact switch points on a single stem up to 3000 mm long. Floats move along the stem and operate reed contacts, so one probe can give low-low, low, normal, high and high-high signals in a tank, or serve as a level and temperature monitor when a Pt100 sensor or a bimetal temperature switch is added at the bottom of the stem. Barksdale describes a wide choice of mounting elements, electrical connections, materials and options so the switch can be designed for the application within the stated dimension limits, with split versions suggested for very long units or large flanges to limit shipping and installation cost.

Technical specifications

Materials, floats and mounting options

The stem and mounting element are brass (CW614N / CW508L) or stainless steel 1.4571 (316Ti). Brass versions use the BN30 float, a 30 mm Buna-N cylinder for media of at least 0.6 g per cubic centimetre, up to 100 C in oil (80 C in water) and 15 bar. Stainless versions use three float types, all in 1.4571: VA44, a 44 mm cylinder for 0.84 g per cubic centimetre or more, 150 C and 15 bar; VA52, a 52 mm ball for 0.78 or more, 150 C and 40 bar; and VA80, an 80 mm ball for 0.54 or more, 150 C and 17 bar. Mounting elements include a G3/8 inside thread, G1 or G2 tank screws, a 2 inch NPT tank screw, DIN 2527 flanges DN 65, DN 80 and DN 100 (PN16) and ASME B16.5 flanges in 2, 3 and 4 inch Class 150 RF, with restrictions by float type shown in the code table. Maximum operating pressure is 40 bar, depending on mounting element and float.

Switch points, contacts and electrical connections

Up to six switch points are available (L1 to L6), but the maximum depends on the electrical connection group: a KL6 terminal box takes up to five, KL12 six, ST1 plug two, ST2 plug five and PG or cable versions six on connection group 1, with smaller limits on groups 2 to 4. Contact modes are SPST normally open or normally closed (250 V AC/DC, 3 A, 100 VA/W) or SPDT changeover (140 V AC, 100 V DC, 1 A, 60 VA/W), defined for an empty tank. Electrical connections include a DIN EN 175301-803-A cube plug (ST1), an angle plug (ST2), an M12 x 1 plug, aluminium terminal boxes (KL6, KL12), a cable gland with 1 m PVC cable, sealed cable, and ATEX terminal boxes KX4 and KX8. Options are -U bottom mounting, -HT high temperature (-40 to 150 C, silicone cable), -DR damping tube, -VV vertical adjustment (maximum 5 bar), -PT100, -TPxx/2 temperature switch (50, 60, 70, 80 or 90 C) and -Exi.

Ex approval, ordering and what to confirm

The Exi version is certified TUV 18 ATEX 214370 X and IECEx TUN 17.0039X: Ex ia IIB T6 for Buna-N and plastic floats and the ST1 plug, and Ex ia IIC T6 for other float switches, with Ui = 28 V, Ii = 125 mA and Pi = 0.5 W. Six switch points (L6) and some connections (KL6, KL12, ST2) are not covered by the ATEX certificate. To order, give the stem material, mounting element, connection, float, number of switch points, contact mode, total length L0 and each switch point distance L1, L2 and so on, plus options; the datasheet example is L0 = 200 mm with L1 = 150 mm normally closed and L2 = 85 mm normally open. Protection is IP65 for plug, terminal box and cable gland designs, IP54 for the K cable design, IP67 or IP68 on request, and the switch must be installed vertically within plus or minus 30 degrees. Confirm the fluid density against the float minimum and the datasheet note that the minimum dimensions are based on water. The attached file is the four-page Barksdale datasheet. More level products are in level instrumentation; send the code and lengths for a quotation.

How the Barksdale UNS2000 works

Floats slide along a vertical stem and carry magnets. A magnet closes a reed contact inside the stem when the float reaches its position. Each contact gives a switch signal at one level.

Where the UNS2000 is used

• Storage tanks
• Process vessels
• Pump control
• Multi-level alarms
• Level and temperature monitoring

Selection checklist for the UNS2000

• Stem length
• Number of switch points
• Stem and mounting material
• Float type
• Medium density
• Operating pressure
• Temperature and cable type
• Temperature sensor option

Installation, commissioning and maintenance notes for the UNS2000

Mount the switch vertically through the top or the bottom of the tank. Set the switch points and wire the contacts. Check the floats and the contacts at regular intervals.

Requesting a quotation for the Barksdale UNS2000

Please send the stem length, the switch points and the medium needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

UNS2000 switch type

It is a vertical multi-level float switch.

UNS2000 maker

It is made by Barksdale.

UNS2000 switch points

It carries up to six reed-contact switch points.

UNS2000 stem

All the switch points sit on one stem.

UNS2000 length

The stem is up to 3000 mm long.

UNS2000 tank signals

One probe can give low-low, low, normal, high and high-high signals.

UNS2000 temperature option

A Pt100 sensor can be added at the bottom of the stem.

UNS2000 bimetal switch

A bimetal temperature switch of 50 to 90 degrees C is an option.

UNS2000 split versions

Split versions suit very long units or large flanges.

UNS2000 stem material

The stem is brass or stainless steel 1.4571.

UNS2000 brass float

Brass versions use the BN30 float.

UNS2000 BN30 float

The BN30 is a 30 mm Buna-N cylinder.

UNS2000 stainless floats

Stainless versions use the VA44, VA52 or VA80 float.

UNS2000 VA44 float

The VA44 is a 44 mm cylinder.

UNS2000 VA52 float

The VA52 is a 52 mm ball.

UNS2000 VA80 float

The VA80 is an 80 mm ball.

UNS2000 pressure

The operating pressure is up to 40 bar and depends on the mounting and float.

UNS2000 PVC cable

With PVC cable the temperature runs from minus 10 to plus 105 degrees C.

UNS2000 silicone cable

With silicone cable the temperature runs from minus 40 to plus 150 degrees C.

UNS2000 contacts

Contacts are SPST normally open or normally closed.

UNS2000 contact rating

The SPST contact is rated 250 V AC/DC and 3 A.

UNS2000 changeover contact

An SPDT changeover contact is also available.

UNS2000 mounting position

It mounts vertically within 30 degrees.

UNS2000 other options

Options include a damping tube, bottom mounting and vertical adjustment.

Level records for the Barksdale UNS2000

Record the tag, the switch points and the date of each check.

Choosing the right UNS2000 float and stem

Choose the float and the stem from the medium density and the temperature.