1638-0 Series 1630 Large Diaphragm Pressure Switches
Large diaphragm pressure switch, range 0.05-0.25" w.c., approx deadband @ 0.04 min. set point, 0.05 max. set point.
Supported Applications
The Dwyer Series 1630 Large Diaphragm Pressure Switch is a high-precision conventional switch designed for maximum dependability in HVAC and industrial service. The series measures differential pressure using air or non-combustible, compatible gases. It incorporates a visible set point indicator to simplify operation and troubleshooting.
Operating Conditions & Performance
The Series 1630 operates within temperature limits of -30°F (-34.4°C) for dry air or gas to 110°F (43.3°C). The switch is rated for a continuous pressure of 10 psig (68.95 kPa) and can withstand a surge pressure of 25 psig (172.4 kPa). Repeatability is specified as ±1%. Electrical capability supports up to 15 A @ 120 to 480 VAC, 60 Hz resistive loads, or 1/8 HP @ 125 VAC and 1/4 HP @ 250 VAC. The switch type is SPDT with a screw-type set point adjustment featuring an enclosed scale.
Measurement Ranges
The series offers five distinct operating ranges in inches of water column (in w.c.):
• 1638-0: 0.05 to 0.25 in w.c.
• 1638-1: 0.20 to 1.0 in w.c.
• 1638-2: 1.0 to 3.0 in w.c.
• 1638-5: 2.0 to 6.0 in w.c.
• 1638-10: 3.0 to 12.0 in w.c.
The approximate dead band varies by model and set point, ranging from 0.04 at the minimum set point for Model 1638-0 up to 0.30 at the maximum set point for Model 1638-10.
Configuration Options
The Series 1630 is available in multiple configurations including standard pressure switches, models with conduit connections (Model 1638), and models without conduit (Model 1639). The process connection is a 1/8" female NPT. Electrical connections utilize three screw terminals for common, normally open, and normally closed circuits.
Housing and Environmental Options
Standard housings are constructed of 16 ga. steel, zinc plated, and dichromate dipped to pass a 200-hour salt spray test. The diaphragm is made of silicone rubber with a stainless steel calibration spring. Additional options include:
• -WP: Weatherproof housing (switch must be installed at the factory).
• -EXPL: Explosion-proof housing.
• -MIL: Environmental construction for high humidity or government applications, utilizing a special snap switch and silicone rubber diaphragm. This configuration is designated as Model 1635 (e.g., 1635-5-MIL) and features a slightly greater dead band than the standard model.
• -AT: Aluminum tag.
• -ST: Stainless steel tag.
Key Product Differences
The series distinguishes between Model 1638, which includes a conduit connection (typically 7/8" diameter), and Model 1639, supplied without the conduit. The unlisted Model 1635 is specifically configured for high humidity environments or government specifications with modified internal switching components.
Installation requires mounting the switch with the diaphragm in a vertical position; re-calibration may be necessary if mounted otherwise. Agency approvals include CSA, FM, and UL listings for general service applications.
| Electrical Connections | Screw Terminal |
| Mounting Orientation | Vertical Diaphragm |
| Operating Temperature, Max | 110 °F |
| Operating Temperature, Min | -30 °F |
| Measurement Pressure Type | Gauge |
| Process Connection size | 1/8 in |
| Process Connection Type | NPT Female |
| Proof Pressure | UP to 10 psi |
| Repeatability | ± 1% |
| Series ID | Series-1630 |
| Set Point Adjustment | Internal Screw |
| Switch Note | 15 A @ 120-480 VAC, 60 Hz. Resistive, 1/8 HP @ 125 VAC,1/4 HP @ 250 VAC, 60 Hz |
| Switch Rating | 15 A @ 120-480 Vac, 1/8 HP @ 125 Vac, 1/4 HP @ 250 Vac |
| Switch Type | SPDT NO/NC, Selectable |
| Weight | 1.5 kg |