Omega DSS User guide

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Series DSS Direct-Contact Speed Switch

REAR VIEW

MOUNTING HOLE PLAN

Specications - Installation and Operating Instructions

4-7/8

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ø4-3/4

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3/4˝ NPT PIPE TAP

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BOTH SIDES

Bulletin E-17

3/8

[9.53]

The Series DSS Direct-Contact Speed Switch is a compact switch designed to include all mechanical and electronic components in one housing. It will produce an output signal at a predetermined speed which may be either over-speed, under-speed or zero-speed. Rugged, heavy-duty construction combined with solid state electronics and photo-electric technology makes this one of the most advanced motion detectors available. Series DSS protects all valuable rotating equipment including belt conveyors, bucket elevators, rotary feeders or screw conveyors. It operates in a clockwise or counter-clockwise direction and mounts in any position.

FRONT VIEW SIDE VIEW

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SPECIFICATIONS Ambient Temperature Range: 14°F to 131°F (-10°C to +55°C). Max. Operating Temperature: DSS-E: Class T6: 185°F (85°C). Enclosure: Aluminum with screw cover. Enclosure Rating: DSS-W: NEMA 3S, 4 and 4X. DSS-E: NEMA 3S, 4 and 4X,

NEMA 7: Class I groups C and D, NEMA 9: Class II groups F and G, class III.

Switch Type: DPDT. Electrical Rating: 3A @ 120/240 VAC, 1/10 Hp @120/240 VAC. Electrical Connections: Screw terminal. Conduit Connections: (2) 3/4˝ female NPT. Mounting Orientation: Any. Set Point Adjustment: Adjustment screw. Power Requirements: 105-135 VAC, 50/60 Hz, 210-250 VAC, 50/60 Hz; or 24

VAC/DC depending on model.

Power Consumption: 3 W. Repeatability: 2% max. at constant voltage and temperature. Pick-up Point: 3 speed ranges at which relay will energize: Low: 0.1 to 10 RPM;

Medium: 1 to 100 RPM; High: 10 to 1000 RPM. Signal Point: Speed at which relay will de-energize. Recommended to be 15-20% lower than pick-up point.

Start-up Delay: Adjustable up to 45 s. Radial Load on Input Shaft: 125 lbs max. End Thrust on Input Shaft: 100 lbs max. Rotation: Either clockwise or counter-clockwise. Driving torque: 1˝/lb max. Shaft: 5/8˝ diameter with 3/16˝ x 7/8˝ key; Weight: 5 lbs

(2.3 kg). Compliance: cUL, UL.

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DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219-879-8000

Fax: 219-872-9057

www.dwyer-inst.com

e-mail: [email protected]

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OPERATING PRINCIPLE

CUSTOMER’S SHAFT WITH

CUSTOMER’S SHAFT WITH CONCENTRIC STUB SHAFT

NORMALLY OPEN 2

NORMALLY CLOSED 2

The Series DSS Motion Switch senses motion by means of a precision metal disc mounted on the input shaft. This disc generates measurable light pulses by a series of slots on its periphery, which rotate past an infrared light source. A photo-electric sensor monitors the series of light pulses and converts them to digital electronic signals. Solid state circuitry then analyzes the digital signals and activates or deactivates the output relay at the pre-set speed. Field adjustment of the signal set point is easily accomplished by means of an adjustment screw on the electronics. For under-speed sensing, the signal point is set below the normal operating speed of the unit. The output relay will then de-energize if the speed drops below the signal point. For overspeed sensing, the pick-up point is set above the normal operating speed. The output relay will energize if the speed exceeds the pick-up point. Zero-speed sensing can be accomplished by turning the adjustment screw to its minimum setting. The output relay will then de-energize when the shaft speed of the unit approaches zero.

INSTALLATION LOCATION AND MOUNTING

The Series DSS motion switch can be mounted for operation in any position. The

surface to which the switch is afxed should be as at and as smooth as possible.

Bearing brackets and shim plate sets can be used to mount the unit directly to the pillow block supporting a shaft. On installations where vibration conditions are not

extreme, use 1/4˝ diameter machine bolts with lock washers through the four mounting

holes in the base of the switch. (Mounting bolts and lock washers are not furnished with the switch.) If vibration conditions are extreme, use of a doweling is recommended through two mounting holes in the switch base. The switch should be mounted as axially in line, and/or parallel as possible to the existing shaft, which is to drive the switch. The Series DSS motion switch can be driven by one of the following means:

1. Direct connection through a coupling (preferred means). Note: Switch should be concentric with the mating shaft. If stub is used, it must be concentric with the main

shaft. If a stub shaft is required, we suggest the use of a 5/8˝ stub shaft. Use with a split or exible type coupling.

CONCENTRIC STUB SHAFT

FLEXIBLE COUPLING

Figure 1: Suggested coupling arrangement, side view

WIRING

USE ONLY SOLID

CONDUCTORS OF

14 AWG OR SMALLER

GREEN L.E.D. INDICATES

RELAY ENERGIZED

YELLOW L.E.D.

INDICATES PULSES

NORMALLY OPEN 1

NORMALLY CLOSED 1

COMMON 1

SPEED SET POINT

COMMON 2

LINE VOLTAGE

SPEED RANGE

LHM

TIME DELAY

Figure 4: Electronics view

Remove end cap to expose terminals and pick-up speed adjustment screw. Wire input power from source to terminals L1 & L2. Be certain to use the provided ground screw. The output of the Series DSS is a DPDT relay. There are two sets of output contacts. Each set includes normally open, normally closed and common. As a result, the unit can be used to control two separate circuits such as a motor starter and a signal light.

CONDUIT INSTALLATION

Use only hubs of suitable sizes that are UL/CSA approved for WATERTIGHT use. Install per the hub manufacturer’s instructions. Be sure the location selected will provide adequate wire bending space.

SIGNAL SET POINT FOR USE AS AN UNDER-SPEED SWITCH

Select the speed range required by changing the switch to LOW for 0.1 to 10 RPM, MEDIUM for 1 to 100 RPM and HIGH for 10 to 1000 RPM. Turn the set point potentiometer to the counter-clockwise stop. With motion present on the input shaft and at normal operating RPM, the yellow LED should blink. The green LED should turn on indicating that the output relay is energized. Slowly turn the set point adjustment screw clockwise until the output relay de-energizes. (A “click” will occur at this point.) Back up until the output relay energizes. Thus, when speed drops below the set point, the green LED should turn off indicating that the output relay is de-energized. If the normal operating speed of the input shaft exceeds 10 RPM for the LOW, 100 RPM for the MEDIUM or 1000 RPM for the HIGH, the unit should be adjusted as follows. Turn the set point adjustment screw clockwise until it reaches the stop. When the speed drops below 10 RPM for the HIGH, the relay will energize. Note: Typically, the motor contact is wired in series with one of the NO output contacts and an alarm is wired with one of the NC output contacts.

A V-Belt drive is not as desirable because of possible slippage.

COG BELT (TIMING) OR

ROLLER CHAIN DRIVE

Figure 2: Cog belt drive (timing) or roller chain drive:

SPUR GEARS

Figure 3: Suggested spur gear arrangement (top view)

FOR USE AS A ZERO-SPEED SWITCH

Select the HIGHEST speed range by changing the switch to HIGHEST for 0.1 to 10 RPM. Turn the set point potentiometer to the counter-clockwise stop. This will give a set point of 0.1 RPM. Thus, when the speed drops below 0.1 RPM, the output relay will de-energize. Note: Wiring should be the same as for under-speed applications.

TIME DELAY SETTING

The Series DSS motion switch has a start-up delay that is adjustable up to 45 seconds. This setting should be set, depending on the application and the length of time it takes for the conveyor to reach its normal operating RPM. This time delay takes effect upon power-up of the Series DSS after shutdown. AC power to the Series DSS must be interrupted for timer to be reset. This delay only effects start-up, avoiding nuisance start-up alarms.

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TROUBLESHOOTING Problem Solution

• No pulses from yellow LED

• Relay is not energized or de-energized

• Alarm sounds when equipment is started

• Equipment is not shut off when

expected

MAINTENANCE

Upon nal installation of the Series DSS Direct-Contact Speed Switch, no routine

maintenance is required. A periodic check of the system calibration is recommended.

The Series DSS is not eld serviceable and should be returned if repair is needed (eld repair should not be attempted and may void warranty). Be sure to include a

brief description of the problem plus any relevant application notes. Contact customer service to receive a return goods authorization number before shipping.

• Check power supply. Make sure input shaft is turning.

• Check power supply. When expected. (I.e. green LED not on: Make sure input shaft is turning. Or off when expected.) Check for proper set point. Check for proper speed setting. (LOW, MEDIUM or HIGH)

• Check startup delay setting. Check for proper connections between alarm and relay. AC power must be interrupted for alarm to reset.

• Check power supply. Check for proper connections between alarm and relay.

• Check power supply. Check for proper connections between control circuit and relay.

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