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Series 1950G Explosion-Proof Differential Pressure Switch

Series AT-ADPS ATEX/IECEx Approved Differential Pressure Switch

Series 1640 Floating Contact Null Switch for High and Low Actuation

Visual Set Point Adjustment, Adjustable Null Zone

The unique electric switch design in the Series 1640 Floating Contact Null Switch for High and Low Actuation is another Dwyer Instruments, LLC innovation. The Dwyer® Model 1640 Differential Pressure Switch resembles the high precision large diaphragm Series 1630 switches. However, the Model 1640 is equipped with a single pole, double throw floating contact switch (not snap acting) so it functions as a null switch.
As the diaphragm moves in response to pressure changes, it moves the floating contact to cause switching action at two preset points with no switching action between these points. The “high” circuit will be closed when rising pressure differential reaches the preset level. The “low” circuit will be closed when falling pressure differential reaches the preset level.

CAUTION: FOR USE ONLY WITH AIR OR COMPATIBLE GASES.

Product Applications

Damper positioning
Duct air control

Starting at $830.35

Ordering

Grouped product items
Model	Description	Availability*	Price
1640-0	Floating contact null switch, range .01-0.2" w.c., adj. null span, .01 min. set, .03 max. Set.	Call for Details*	$830.35
1640-1	Floating contact null switch, range 0.2-1.0" w.c., adj. null span, .02 min. set, .06 max. Set.	Call for Details*	$830.35
1640-10	Floating contact null switch, range 3.0-12.0" w.c., adj. null span, .04 min. set, .20 max. Set.	Call for Details*	$830.35
1640-2	Floating contact null switch, range 1.0-4.0" w.c., adj. null span, .03 min. set, .12 max. Set.	Call for Details*	$830.35
1640-5	Floating contact null switch, range 2.0-6.0" w.c., adj. null span, .03 min. set, .18 max. Set.	Call for Details*	$830.35

Specifications

Service:: Air and non-combustible, compatible gases.
Wetted Materials:: Consult factory.
Temperature Limits:: -30 to 110°F (-34.4 to 43.3°C).
Pressure Limits:: 10 psig (68.95 kPa) continuous, 25 psig (172.4 kPa) surge.
Switch Type:: SPDT floating contact (not snap action).
Electrical Rating:: Non-inductive: 2.5 A @ 110 VAC, 1.5 A @ 220 VAC, 1 A @ 24 VDC, 0.5 A @ 110 VAC; Inductive: 1 A @ 110 VAC, 0.5 A @ 220 VAC, 0.5 A @ 24 VDC. (De-rate 70-80% for very slow pressure changes.)
Electrical Connections:: 3 screw type.
Process Connections:: 1/8" female NPT.
Mounting Orientation:: Diaphragm in vertical position. Consult factory for other position orientations.
Set Point Adjustment:: Screw type.
Weight:: 4 lb 13 oz (2.18 kg).
Compliance:: CE.

Features

Options

Support Library

Approvals

Drawings

Model Chart

EXAMPLE	1640	0	AT	Series 1640-0-AT Floating Contact Null Switch for High and Low Actuation, range 0.01-0.2" w.c., with aluminum tag.
SERIES	1640			Floating Contact Null Switch for High and Low Actuation
RANGE		0 1 2 5 10 .25KPA 1KPA 1.5KPA 3KPA		0.01 - 0.2" w.c. 0.20-1.0" w.c. 1.0-4.0" w.c. 2.0-6.0" w.c. 3.0-12.0" w.c. 0.05-0.25 kPa 0.4-1.0 kPa 0.5-1.5 kPa 1.0-3.0 kPa
OPTIONS			AT LC PRESET ST	Aluminum Tag Less Conduit Preset Stainless Steel Tag

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