1220 Series Indicating Switches
The Series 1220 Differential Pressure Indicating Switches are used for on-off control or alarm. They also indicate flow, liquid level or other process variables. These units are furnished with one or two SPDT type switches with actuation set points easily adjustable over most of the range of the instrument. The calibrated travel of the pointer is 270° which gives good differential pressure indication and switch resolution. Dials can be supplied with linear scales for differential pressure, square root scales for flow, or custom scales for level. The Series 1220 Switches are used extensively in power plants, compressor stations and cryogenic applications.

Features
1020 & 1120 Accuracy
30” w.c. range 1.50% FS
50” w.c. thru 500 PSID range 0.75% FS
Option: 100” w.c. thru 50 PSID range 0.50% FS

1220 Accuracy
Before switch activation 0.75% FS
At switch activation point 2.00% FS
After switch activation 1.50% FS

Zero Elevation
100% of range (150 PSID maximum)

Suppression
15% of range with 270° pointer travel

Operating Temperature
-60°F to +200°F

Full Scale Displacement
30” w.c. thru 130” w.c. range .19 Cu. In.
135” w.c. thru 60 PSID range .12 Cu. In.
75 PSID thru 500 PSID range .06 Cu. In.

1220 Switch Type
Snap action SPDT

1220 Switch Setting Accuracy
1.00% FS

1220 Dead Band
1 switch (nominal) 7% FS
2 switch (nominal) 10% FS

1220 Switch Setting
Increasing -10 to 100% of differential or 10” of water whichever is greater
Decreasing - 5% or 5” of water whichever is greater
Between set points -15% of FS minimum

1220 Switch Rating
5 amps at 125V or 250V AC
3 amps inductive or 5 amps resistive at 30VDC

Mounting Dimensions
Model 1020 Request File No. 1020:420
Model 1123 Request File No. 1123:420
Model 1124 Request File No. 1124:420
Model 1126 Request File No. 1126:420
Model 1224 Request File No. 1224:420
Model 1226 Request File No. 1226:420
Model 1226X-1 Request File No. 1226X-1:420
Model 1226X-2 Request File No. 1226X-2:420

Ordering Specifications

To order any one of Meriam’s Bellows Gauges, custom made to your specifications, please contact your Meriam
sales representatives with the following information:

• Model Number
• Housing Material
• Safe Working Pressure
• Bellows Material
• Differential Range
• Type of Scale
(Linear or Sq. Rt.)
• Type of Mounting