{"id":7656,"date":"2022-05-18T04:26:22","date_gmt":"2022-05-17T20:26:22","guid":{"rendered":"https:\/\/ancor.biz\/?post_type=product&#038;p=7656"},"modified":"2025-08-18T12:05:55","modified_gmt":"2025-08-18T04:05:55","slug":"dwyer-series-1640-floating-contact-null-switch","status":"publish","type":"product","link":"https:\/\/ancor.biz\/index.php\/product\/dwyer-series-1640-floating-contact-null-switch\/","title":{"rendered":"DWYER Series 1640 Floating Contact Null Switch"},"content":{"rendered":"<h1>Series 1640 Floating Contact Null Switch for High and Low Actuation, Visual Set Point Adjustment, Adjustable Null Zone<\/h1>\n<p>&nbsp;<\/p>\n<p>The unique electric switch design in the\u00a0<a href=\"https:\/\/ancor.biz\/index.php\/product-category\/brand\/dwyer-instruments-brand\/\">DWYER<\/a> Series 1640 Floating Contact Null Switch is another Dwyer Instrument, Inc. innovation. DWYER Series 1640 Floating Contact Null Switch resembles the Series 1630 switches. However, the Series 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 &#8220;high&#8221; circuit will be closed when rising pressure differential reaches the preset level. The &#8220;low&#8221; circuit will be closed when falling pressure differential reaches the preset level.<\/p>\n<p>&nbsp;<\/p>\n<h2 class=\"sub_heading\">Product Applications<\/h2>\n<ul class=\"list-details inline product_feature\">\n<li>Damper positioning<\/li>\n<li>Duct air control<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<section id=\"features\" class=\"ui-tabs-panel ui-widget-content ui-corner-bottom\" role=\"tabpanel\" aria-labelledby=\"ui-id-4\" aria-expanded=\"true\" aria-hidden=\"false\">\n<h1 class=\"tab-heading\">Features<\/h1>\n<ul>\n<li>Floating \u201cnull\u201d switch supports applications requiring two set point actions such as open and close damper control<\/li>\n<li>Visible set point indicator simplifies operation and trouble shooting<\/li>\n<li>Large diaphragm provides low range accuracy providing precise control<\/li>\n<\/ul>\n<\/section>\n<p>&nbsp;<\/p>\n<section id=\"specs\" class=\"ui-tabs-panel ui-widget-content ui-corner-bottom\" role=\"tabpanel\" aria-labelledby=\"ui-id-3\" aria-expanded=\"true\" aria-hidden=\"false\">\n<h1 class=\"tab-heading\">Specifications<\/h1>\n<ul class=\"list-specs lined\">\n<li>Service: Air and non-combustible, compatible gases.<\/li>\n<li class=\"title\">Wetted Materials: Consult factory.<\/li>\n<li class=\"title\">Temperature Limits: -30 to 110\u00b0F (-34.4 to 43.3\u00b0C).<\/li>\n<li class=\"title\">Pressure Limits: 10 psig (68.95 kPa) continuous, 25 psig (172.4 kPa) surge.<\/li>\n<li class=\"title\">Switch Type: SPDT.<\/li>\n<li class=\"title\">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.)<\/li>\n<li class=\"title\">Electrical Connections: 3 screw type, common, normally open and normally closed.<\/li>\n<li class=\"title\">Process Connections: 1\/8&#8243; female NPT.<\/li>\n<li class=\"title\">Mounting Orientation: Diaphragm in vertical position. Consult factory for other position orientations.<\/li>\n<li class=\"title\">Set Point Adjustment: Screw type.<\/li>\n<li class=\"title\">Weight: 4 lb 13 oz (2.18 kg).<\/li>\n<li class=\"title\">Agency Approvals: CE.<\/li>\n<\/ul>\n<\/section>\n<p>&nbsp;<\/p>\n<h2 class=\"tab-heading\">Models &amp; Ordering<\/h2>\n<table class=\"product-table\">\n<tbody>\n<tr>\n<th class=\"model-number\" nowrap=\"nowrap\" width=\"\">Model<\/th>\n<th class=\"description\" width=\"\">Description<\/th>\n<\/tr>\n<tr>\n<td class=\"model-number\" nowrap=\"nowrap\" width=\"\">1640-0<\/td>\n<td class=\"description\" width=\"\">Floating contact null switch, range .01-0.2&#8243; w.c., adj. null span, .01 min. set, .03 max. set.<\/td>\n<\/tr>\n<tr>\n<td class=\"model-number\" nowrap=\"nowrap\" width=\"\">1640-1<\/td>\n<td class=\"description\" width=\"\">Floating contact null switch, range 0.2-1.0&#8243; w.c., adj. null span, .02 min. set, .06 max. set.<\/td>\n<\/tr>\n<tr>\n<td class=\"model-number\" nowrap=\"nowrap\" width=\"\">1640-10<\/td>\n<td class=\"description\" width=\"\">Floating contact null switch, range 3.0-12.0&#8243; w.c., adj. null span, .04 min. set, .20 max. set.<\/td>\n<\/tr>\n<tr>\n<td class=\"model-number\" nowrap=\"nowrap\" width=\"\">1640-2<\/td>\n<td class=\"description\" width=\"\">Floating contact null switch, range 1.0-4.0&#8243; w.c., adj. null span, .03 min. set, .12 max. set.<\/td>\n<\/tr>\n<tr>\n<td class=\"model-number\" nowrap=\"nowrap\" width=\"\">1640-5<\/td>\n<td class=\"description\" width=\"\">Floating contact null switch, range 2.0-6.0&#8243; w.c., adj. null span, .03 min. set, .18 max. set.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Series 1640 Floating Contact Null Switch for High and Low Actuation, Visual Set Point Adjustment, Adjustable Null Zone &nbsp; The unique electric switch design in the\u00a0DWYER Series 1640 Floating Contact Null Switch is another Dwyer Instrument, Inc. innovation. DWYER Series 1640 Floating Contact Null Switch resembles the Series 1630 switches. However, the Series 1640 is &#8230; <a title=\"DWYER Series 1640 Floating Contact Null Switch\" class=\"read-more\" href=\"https:\/\/ancor.biz\/index.php\/product\/dwyer-series-1640-floating-contact-null-switch\/\" aria-label=\"More on DWYER Series 1640 Floating Contact Null Switch\">Read more<\/a><\/p>\n","protected":false},"featured_media":7657,"template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"spay_email":""},"class_list":["post-7656","product","type-product","status-publish","has-post-thumbnail","hentry","product_cat-brand","product_cat-diffrential-pressure","product_cat-dwyer-switch-vacuum","product_cat-dwyer-instruments-brand","product_cat-dwyer-instruments-dwyer-omega","product_cat-dwyer-omega","product_cat-pressure-switch-dwyer-instruments-dwyer-omega","product_cat-switch-vacuum","product_cat-pressure-switch","product_cat-switch","product_tag-1640-0","product_tag-1640-1","product_tag-1640-10","product_tag-1640-2","product_tag-1640-5","product_tag-dwyer-series-1640","product_tag-dwyer-series-1640-floating-contact-null-switch","sales-flash-overlay","woocommerce-text-align-center","woocommerce-image-align-center","do-quantity-buttons"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.3 - 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