Dwyer Instruments L4-SS-MT, L4-SS-TOP, L4-SS-D, L4-TOP, L4-SS User manual

Bulletin E-73

Series L4

Specifications - Installation and Operating Instructions

Rugged and reliable the Flotect®L4 Level switch operates automatically

to indicate tank level. Perfect for starting or stopping pumps, opening or
closing valves, or actuate level alarm signals. A unique magnetically
actuated switching design gives superior performance. There are no
bellows, springs, or seals to fail. Instead, the free-swinging float attracts
a magnet within the solid metal switch body, actuating a snap switch by
means of a simple lever arm. Float arm hinge design limits the arm angle
to prevent vertical hangup.

FEATURES

• Leak proof body machined from bar stock

• Choice of floats dependent on maximum pressure and specific gravity

• Weatherproof, designed to meet NEMA 4

• Explosion-proof (listings included in specifications)

• Installs directly and easily into tank with a thredolet or flange
(see application drawings on page 4)

• Electrical assembly can be easily replaced without removing the unit
from the installation so that the process does not have to be shut down

• Horizontal installation or optional top mount vertical installation

APPLICATIONS

• Direct pump control for maintaining level

• Automatic tank dump operations

• Control levels or provide alarms in sumps, scrubber systems, hydro­pneumatic tanks, low pressure boilers, and various waste
water/sewage treatment processes

Float Switch

SPECIFICATIONS
Service: Liquids compatible with wetted materials.
Wetted Materials:

Float and Rod: 316 SS;
Body: Brass or 316 SS standard;

Magnet Keeper: 430 SS standard, 316 SS or nickel optional.
Temperature Limits: 4 to 275°F (-20 to 135°C) standard, MT high
temperature option 400°F (205°C) [MT option not UL, CSA, ATEX or
IECEx]. ATEX, IECEx options: Ambient temperature -4 to 163°F (-20 to
73°C); Process temperature -4 to 163°F (-20 to 73°C).
Pressure Limit: Brass body 1000 psig (69 bar), 316 SS body 2000 psig
(138 bar). Standard float rated 100 psig (6.9 bar). For other floats see
model chart on next page.
Enclosure Rating: Weatherproof and Explosion-proof. Listed with UL
and CSA for Class I, Groups C and D; Class II, Groups E, F, and G.
ATEX 0518 II 2 G Ex d IIB T6 Gb -20°C≤Tamb≤73°C.

-20°C≤Process Temp≤73°C.
EC-Type Certificate No.: KEMA 03 ATEX 2383.
ATEX Standards: EN60079-0: 2009; EN60079-1: 2007.
IECEx Certified: For Ex d IIB T6 Gb -20°C≤Tamb≤73°C. -20°C≤Process
Temp≤73°C.
IECEx Certificate of Conformity: IECEx DEK 11.0071.
IECEx Standards: IEC 60079-0: 2007; IEC 60079-1: 2007.

Switch Type: SPDT snap switch standard, DPDT snap switch optional.
Electrical Rating: UL, FM, ATEX or IECEx models: 10A @ 125/250 VAC

(V~). CSA models: 5A @ 125/250 VAC (V~); 5A res., 3A ind. @ 30 VDC
(V ). MV option: 1A @ 125 VAC (V~); 1A res., .5A ind. @ 30 VDC (V ).
MT option: 5A @ 125/250 VAC (V~). [MT and MV option not UL, CSA, FM,
ATEX or IECE].
Electrical Connections: UL and CSA models: 16 AWG, 6˝ (152 mm)
long. ATEX or IECEx unit: terminal block.
Process Connection: 1-1/2˝ male NPT standard, 2-1/2˝ male NPT
standard optional floats.
Mounting Orientation: Horizontal installation standard, optional vertical
top mount.

Weight: 4 lb 9 oz (2.07 kg).
Dead Band: 3/4˝ (19 mm) for standard float.
Specific Gravity: 0.7 minimum with standard float. For other floats see

model chart.

W.E. ANDERSON DIV., DWYER INSTRUMENTS, INC.

P.O. BOX 358 • MICHIGAN CITY, INDIANA 46360 U.S. A.

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www.GlobalTestSupply.com

Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]

Example

1-5/8

[41.28]

5

[127.00]

6

[152.40]

19-7/32

[488.16]

8-7/32

[208.76]

5

[127.00]

3

[76.20]

3/4 NPT

1-1/2 NPT

2-1/2

[63.50]

3-11/32

[84.93]

1

2

3

5

6

19-7/32

[488.16]

Ø1-5/8

[41.28]

5

[127.00]

6

[152.40]

MAGNET

KEEPER

430 STNLS.

STL.

FLOAT

316 STNLS. STL

(STANDARD)

FLOAT ARM & BLOCK

316 STNLS. STL.

OR BRASS

SWITCH BODY

BRASS OR

316 STNLS. STL.

1-1/2 MALE NPT

MOUNTING CONNECTION

16 GA. LEADS

6 [152.40] LONG

3

[76.20]

5

[127.00]

8-7/32

[208.76]

Ø2-1/2

[63.50]

3-11/32

[84.93]

3/4 FEMALE NPT
CONDUIT
CONNECTION

Construction

Wetted Material
Options

Switch Options
Float Options

Other Options

Flange*
Flange Size

Flange Material

Flange Rating

Bushing*
Bushing Size

Bushing Type

Bushing
Material

* Options that do not have ATEX or IECEx

Attention: Units without the “AT” suffix are not Directive 94/9/EC (ATEX) compliant. These units are not intended for use in potentially hazardous atmospheres in the EU.
These units may be CE marked for other Directives of the EU.

L4
L4
L4-TOP

SS

SS
316
NI

D

C

F

2

C

1

L4-SS-D-C-F2C1
Side Mount, Brass Body, SPDT Switch
Top Mount, Brass Body, SPDT Switch (Specify rod length)
316 SS Body with 430 SS Magnet Keeper
316 SS Body and Magnet Keeper (Order with SS option)
Nickel 20 Magnet Keeper

D

50
150
300

AT
IEC
EPOXY
MT
MV
NB
NH
TBC
TRD
TRI

F

2
3
4

B

1
2
4

DPDT Switch
2-1/2˝ Spherical, 304 SS rated 50 psi (3.5 bar), > 0.5 s.g.
2-1/2˝ Spherical, 316 SS rated 150 psi (10.3 bar), > 0.7 s.g.
2-1/2˝ Spherical, 304 SS rated 300 psi (20.7 bar), > 0.7 s.g.
ATEX
IECEx
Epoxy Coated Housing
High Temperature* (See specifications for rating)
Gold Contact Snap Switch* (See specifications for rating)
Neoprene Boot*
No Electrical Housing*
Terminal Block Wire Connections*
Time Delay Relay* (On flow decrease)
Time Delay Relay* (On flow increase)
Flange Process Connection
2˝
3˝
4˝

C

Carbon Steel

S

316 SS

1

150 #

3

300 #

6

600 #

9

900 #
Bushing Process Connection
2˝
2-1/2˝
4˝

H

Hex

F

Flush

B

Brass

C

Carbon Steel

S

316 SS

4

304 SS

PARTS LIST

1. Cover lock. (ATEX/IECEx unit only).

2. External ground. (ATEX/IECEx unit only).

3. Enclosure housing and cover.

4. Terminal block. (ATEX/IECEx unit only,

UL/CSA unit

UL/CSA unit has 6˝ leads).

5. Internal ground.

*6. Magnet arm and switch assembly.

7. Switch body.

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ATEX/IECEx unit

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*8. Float, arm and block assembly.

*Approved replacement parts

ulletin E-73

FRONT VIEW DETAIL SIDE VIEW DETAIL

CLAMP

S

CREW

L

OCKWASHER

CONDUCTOR

B

INSTALLATION

NOTES:

• Check all ratings given in the instructions and on the product to make
sure that the product is suitable for your application. Do not exceed
electrical ratings, pressure ratings, or temperature ratings of the product.

• Disconnect power supply before beginning installation to prevent
possible equipment damage or electrical shock.

1. Remove packing material from switch body-cap and remove tape from
magnet keeper. Install standard switch in thredolet previously welded to
tank. Install optional switch mountings per application drawings. Make
sure locknuts on float are tight.

2. When mounting switch in the side of a tank, the arrow on the side of
the switch must point up.

3. Wiring: UL and CSA units only: Thread connecting wires through
conduit and connect. Wire in accordance with local electrical codes.

Black - Common
Blue - N.O.
Red - N.C.

NOTE: Double pole, double throw switches have dual black, blue and
red leads. These are connected in the same manner as single pole,
double throw switches, as described above.

ATEX and IECEx Installation Instructions:

Cable Connection
The cable entry device shall be certified in type of explosion
protection flameproof enclosure “d”, suitable for conditions of use
and correctly installed. Cable entry may exceed 70°C. Conductors
and cable gland rated ≥90°C shall be used.

NOTE: ATEX and IECEx units only: The temperature class is
determined by the maximum ambient and/or process temperature. Units
are intended to be used in ambient of -20°C ≤Tamb≤73°C. Units may be
used in process temperatures up to 133°C providing the enclosure and
switch body temperature do not exceed 73°C. The standard
Temperature Class is T6 Process Temp ≤73°C.

5. For units supplied with both internal ground and external bonding
terminals, the ground screw inside the housing must be used to ground
the control. The external bonding screw is for supplementary bonding
when allowed or required by local code. When external bonding
conductor is required, conductor must be wrapped a minimum of 180°
about the external bonding screw. See below.

Conduit Connection
An Ex d certified sealing device such as a conduit seal with setting
compound shall be provided immediately to the entrance of the
valve housing. Cable entry may exceed 70°C. Conductors and cable
gland rated ≥90°C shall be used.

NOTE: The switch is deactivated and contacts are in normal condition

SPDT DPDT

TERMINAL CONNECTIONS

when the liquid is below the float.

4. Make sure conduit or cable are properly sealed. Electrical
components must be kept free of moisture, including condensation, at all
times.

MAINTENANCE

Inspect and clean wetted parts at regular intervals. The cover should be
in place at all times to protect the internal components from dirt, dust,

CAUTION: To prevent ignition of hazardous atmosphere, disconnect the
device from the supply circuit before opening. Keep assembly tightly
closed when in operation.

and weather, and to maintain hazardous location ratings. Disconnect
device from the supply circuit before opening to prevent ignition of
hazardous atmosphere. Repairs to be conducted by Dwyer Instruments,
Inc. Units in need of repair should be returned to the factory prepaid.

Limited Warranty: The Seller warrants all Dwyer instruments and equipment to be free from defects in workmanship or material under normal use and service for a period
of one year from date of shipment. Liability under this warranty is limited to repair or replacement F.O.B. factory of any parts which prove to be defective within that time or
repayment of the purchase price at the Seller’s option provided the instruments have been returned, transportation prepaid, within one year from the date of purchase. All
technical advice, recommendations and services are based on technical data and information which the Seller believes to be reliable and are intended for use by persons
having skill and knowledge of the business, at their own discretion. In no case is Seller liable beyond replacement of equipment F.O.B. factory or the full purchase price. This
warranty does not apply if the maximum ratings label is removed or if the instrument or equipment is abused, altered, used at ratings above the maximum specified, or otherwise
misused in any way.

THIS EXPRESS LIMITED WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER REPRESENTATIONS MADE BY ADVERTISEMENTS OR BY AGENTS AND ALL
OTHER WARRANTIES, BOTH EXPRESS AND IMPLIED. THERE ARE NO IMPLIED WARRANTIES OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR
PURPOSE FOR GOODS COVERED HEREUNDER.

Buyers Remedies: THE BUYER’S EXCLUSIVE AND SOLE REMEDY ON ACCOUNT OF OR IN RESPECT TO THE FURNISHING OF NON-CONFORMING OR DEFECTIVE
MATERIAL SHALL BE TO SECURE REPLACEMENT THEREOF AS AFORESAID. THE SELLER SHALL NOT IN ANY EVENT BE LIABLE FOR THE COST OF ANY LABOR
EXPENDED ON ANY SUCH MATERIAL OR FORM ANY SPECIAL, DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES TO ANYONE BY REASON OF THE FACT THAT
IT SHALL HAVE BEEN NON-CONFORMING OR DEFECTIVE.

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APPLICATION DRAWINGS FOR FLOTECT

2-1/2
THREDOLET

CUT HOLE
2-7/8 [73] DIA.

2-1/2 X 1-1/2
FACE BUSHING

HORIZONTAL, 2-1/2 THREDOLET INSTALLATION
WITH OPTIONAL 2-1/2 [64] SPHERICAL FLOAT

ANSI RF THREADED
REDUCING FLANGE

HORIZONTAL, FLANGE INSTALLATION

3/4 NPT

11-3/4
[298.5]

STANDARD INSTALLATION

1-1/2 THREDOLET

CUT HOLE 1-15/16 [49] DIA.

3/4 NPT

ANSI RF
THREADED
REDUCING
FLANGE

*FLANGE FACE TO CENTERLINE OF FLOAT
SPECIFIED BY CUSTOMER NORMALLY
SHOULD NOT EXCEED 20' [508 MM].

VERTICAL, FLANGE INSTALLATION

AUTOMATIC FLOAT SWITCHES

®

© Copyright 2014 Dwyer Instruments, Inc.

W.E. ANDERSON DIV., DWYER INSTRUMENTS, INC.

P.O. BOX 358 • MICHIGAN CITY, INDIANA 46360 U.S. A.

Find Quality Products Online at: [e-mail]

Printed in U.S.A. 9/14

Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]

www.GlobalTestSupply.com

FR# 82-440631-00 Rev. 5