美國(guó)* 德威爾 dwyer 1640系列用于三位控制的微差壓開關(guān)
可視可調(diào)設(shè)定點(diǎn)，可調(diào)盲區(qū)
1640系列 用于三位控制的微差壓開關(guān)是在1630系列開關(guān)的基礎(chǔ)上創(chuàng)新出來的微差壓開關(guān)，它帶有一個(gè)單刀雙擲的浮動(dòng)觸點(diǎn)開關(guān)，能保持開關(guān)在一個(gè)中間位置。
示意圖展示了工作原理：當(dāng)隔膜被差壓推動(dòng)，它帶動(dòng)浮點(diǎn)開關(guān)在兩個(gè)預(yù)設(shè)點(diǎn)產(chǎn)生動(dòng)作，如果在預(yù)設(shè)點(diǎn)之間，開關(guān)沒有任何動(dòng)作。當(dāng)差壓升高到高預(yù)設(shè)點(diǎn)時(shí)，高位開關(guān)關(guān)閉，當(dāng)差壓降低到低預(yù)設(shè)點(diǎn)時(shí)，低位開關(guān)關(guān)閉。
典型的應(yīng)用例子為馬達(dá)驅(qū)動(dòng)的風(fēng)門，當(dāng)風(fēng)管中的靜壓增大到zui大預(yù)設(shè)點(diǎn)時(shí)，開關(guān)會(huì)控制驅(qū)動(dòng)風(fēng)門位置變化，當(dāng)靜壓降低到zui小預(yù)設(shè)點(diǎn)時(shí)，開關(guān)也會(huì)驅(qū)動(dòng)風(fēng)門位置表話。如果采用皮托管配合使用，是一樣的道理來控制風(fēng)速，是供風(fēng)管保持恒量供風(fēng)。
注意：只能用于空氣或其它兼容性氣體。
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: Single-pole double throw (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, common, normally open and normally closed.
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).
Agency Approvals: CE.
