Dwyer F7 Series Liquid Level Switches Installation Guide

: June 15, 2024
: Dwyer

Table of Contents

Specifications – Installation and Operating Instructions
SWITCH ACTION (Normally open/Normally closed)
INSTALLATION
MOUNTING
SPECIFICATIONS
CIRCUIT INFORMATION FOR REED SWITCH PROTECTION
DWYER INSTRUMENTS, LLC
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

Dwyer F7 Series Liquid Level Switches Installation Guide

Specifications – Installation and Operating Instructions

Installation

F7-HPS-2, EXTERNAL HORIZONTAL MOUNT

F7-HPS-2, INTERNAL HORIZONTAL MOUNT

Dimensions, Inches [mm]

Model| (A) Stem Length| (B) Float Diameter| (C) Float Height| (D) Actuation from HEX
F7-SB| 2.75 [70]| 1.13 [29]| 1.38 [35]| 1.0 [26]
F7-SS2| 2.06 [52]| 1.0 [25]| 1.0 [25]| 0.73 [19]
F7-PP| 2.18 [55]| 1.18 [30]| 1.0 [25]| 0.69 [18]
F7-BT| 2.18 [55]| 1.18 [30]| 1.0 [25]| 0.69 [18]
F7-MPP| 1.63 [41]| 0.63 [16]| 0.63 [16]| 0.47 [12]

SWITCH ACTION (Normally open/Normally closed)

Vertical Models
Vertical mount models are shipped with normally open switch contacts which close as the float rises toward the mounting threads. Reverse switch action by removing the float, rotating it end-for-end and replacing it on the stem.
Horizontal Models
Contacts in horizontal models F7-HPS-1 (internal mount) and F7-HPS-2 (external mount), are normally open when the float is down and normally closed when the float is up. Models F7-HPS-1 and -2 also have indicating arrows on the stem end to confirm float alignment. See installation notes on reverse. Horizontal model F7-HSS is in the normally open position when the indicating arrow points up, and normally closed when the arrow points down.

INSTALLATION

Choose a location away from fill pipes, drains, or other areas where turbulence or wave motion might occur. Turbulence will cause false actuations and shorten contact life. Excess contaminants in fluid may inhibit float operation and occasional wipe-down may be necessary. Care should be taken that switches are always operated within electrical ratings. Read and understand all safety precautions on back of this sheet before installing.

MOUNTING

Install vertical mount models in an appropriate 1/8˝ NPT fitting. Vertical models mount internally, oriented within 30° of vertical, or select optional fittings for external mounting. Model F7-HPS-1 must be mounted internally, which means the switch must be secured to the wall of the tank or vessel from the inside. Install horizontal model F7-HPS-1 in a 5/8˝ (16 mm) hole and secure with nut provided. Tank wall should not exceed 1/8˝ (3 mm). Model F7-HPS-2 requires a horizontal 1/2˝ NPT(F) fitting and can be fitted to the tank or vessel from the outside. Model F7-HSS requires a horizontal 1/2˝ NPT(F) fitting and can be mounting from the inside or outside (internally or externally) of the tank or vessel.

SPECIFICATIONS

Electrical Rating (Maximum): F7-SB, SS2: Power: 50 W any combination of V and A not to exceed 200 V (DC or AC peak) or 1.5 A (DC or AC peak); F7-PP, BT, HSS: AC: 30 VA, 0.14 A @ 200 V; DC: 0.28 A @ 24 V, 0.07 A @ 120 V. F7-MPP: 10 VA, 0.1 A @ 120 VAC; F7-MPP-NO: 50 VA, 0.2 A @ 240 VAC; F7-HPS: 15 VA, 1 A @ 220 VAC/DC

Mounting Connections: 1/8˝ NPT(M) (all vertical mount), 1/2˝ NPT(M) (F7-HPS-2, F7-HSS), M16 x 2 (F7-HPS-1).
Wire Leads: F7-SB, SS2, PP, BT: 22 AWG x 18˝ (46 cm); F7-MPP, HSS: 22 AWG x 24˝ (61 cm); F7-HPS: 22 AWG x 39˝ (1 m).

Enclosure Rating: F7-HSS: Explosion-proof, Class I, Groups A, B, C, D; Class II, Groups E, F, G; Class III.
Weight: F7-SB, 2 oz. (58 g); F7-SS2, 1.2 oz. (34 g); F7-PP, 0.8 oz. (23 g); F7-BT, 0.7 oz. (20 g); F7-HPS-1, 1.5 oz. (43 g); F7-HPS-2, 2 oz. (57 g); F7-HSS, 3 oz. (94 g); F7-MPP, 0.8 oz. (23 g).

MODEL CHART

Model| Material Float/Stem| Maxterms.| MaxPreps.| Mids..| Approx. Deadland
Vertical Mount
F7-SB| Buna-N and Epoxy/316 SS| 220°F| 150 psig| 0.60| 1/16˝
| | 105°C| 10 bar| | 2 mm
F7-SS2| 316 SS (CYC)/316 SS| 300°F| 450 psig| 0.75| 1/16˝
| | 149°C| 31 bar| | 2 mm
F7-PP| Polypropylene and| 220°F| 100 psig| 0.60| 1/8˝
| Epoxy/Polypropylene| 105°C| 6.89 bar| | 4 mm
F7-BT| Buna-N and Epoxy/PBT| 220°F| 150 psig| 0.45| 1/8˝
| | 105°C| 10 bar| | 4 mm
F7-MPP| Polypropylene /| 176°F| 100 psig| 0.90| 1/8˝
| Polypropylene| 80°C| 6.89 bar| | 4 mm
Horizontal Mount
F7-HPS| Polysulfone/| 185°F| 150 psig| 0.85| 3/16˝
-1, -2| Polysulfone| 85°C| 10 bar| | 5 mm
F7-HSS| 316 SS/316 SS| 392°F| 300 psig| 0.60| 1/8˝
| | 200°C| 20.7 bar| | 4 mm
PBT – Polybutylene Terephthalate

Optional Fittings (for Exterior Mounting of Vertical Models)
A-347, 1/8˝ x 1-1/4˝ NPT C.S. adapter.
A-347- SS, 1/8˝ x 1-1/4˝ NPT 316 SS adapter.
A-348, 1/8˝ x 1-1/2˝ NPT C.S. adapter.
A-348-SS, 1/8˝ x 1-1/2˝ NPT 316 SS adapter

Installation notes – Do not subject reed switch controls to excessive shock or vibration or any of the following:

Bending or placing force loads on reed switch housing.
Over-torquing fittings on reed switch housing.
Placing pull-out force on lead wires

Do not exceed 1.5 pounds/ foot (2 n/m) tightening torque. Excessive torque may cause premature switch element or housing failure.
Indicating arrows are provided on the stem ends to confirm float alignment.
Avoid installations where wiring entering the device is submerged or exposed to excessive amounts of liquid or humidity condensate.
Gasket seal for internal mounting units should be preassembled before insertion through tank wall. Wall thickness should not exceed 1/8˝ (3 mm).
When preparing wires for termination, avoid pulling against the resin seal or end plug of the float switch.
Units with tapered pipe threads should be treated with Teflon based thread compound or tape before insertion in fitting. Sufficient torque is achieved at hand-tight plus one half turn

CIRCUIT INFORMATION FOR REED SWITCH PROTECTION

Read information below before installing your new reed switch control!
Exceeding the current capacity of this Reed Switch control may cause FAULTY OPERATION! Be aware of the inductive and capacitive or lamp loads you may be placing on you Reed Switch Control. The circuits below outline possible solutions to preventing overloads due to inrush or surge currents exceeding maximum or when the switch current and product of the inductive back EMF exceed the switch’s power rating. Also the circuit for prevention of overload when switching filament lamps (low “cold” resistance) is outlined below. Failure to follow these measures to protect Reed Switch Contacts may cause the contacts to weld together or result in premature wear.

Inductive loads
Possible causes – An electromagnetic relay, electromagnetic solenoid, electromagnetic counter with inductive component as circuit load.

Possible Circuit Solutions Indicated by Dashed Lines

Capacitive loads
Possible causes – A capacitor connected in series or parallel with Reed Switch control. In a closed circuit, a cable length (usually greater than 50m [162.5 ft.]) used to connect reed switch may also introduce static capacitance.
Solutions Indicated