- Vibration Monitoring
- Industrial Communications
- PLC & I/O Cards
- Automation Accessories
- AC Drives
- Controllers & Data Acquisition
- Industrial Computers
- Encoders
- Safety Switches & Guard Locking
- Isolator & Barrier
- Motor Soft Starters
- CCTV & Security
- HMI Displays
- Automation Software
- Servo Drives
- Pneumatic Cylinders
- Robotics
- Machine Vision
Brand: United Electric controls
United Electric J120 Explosion-Proof Pressure Switch
Description
An explosion-proof pressure switch family with internal or external set point adjustment
The United Electric J120 is the internal-adjustment pressure member of the UE 120 Series, a range of explosion-proof pressure, vacuum, differential pressure and temperature switches. It has one SPDT switch in an epoxy-coated die-cast aluminium enclosure with dual conduit entries and an internal set point lock. The enclosure is certified Type 4X and IP66, and the Class I Division 1 version meets Type 7. Sensor styles A to K cover vacuum and ultra-low pressure through high-pressure ranges, with wetted materials from Buna-N and aluminium to welded 316L stainless steel, so the switch can be matched to the process medium.
Technical specifications
| Parameter | Specification |
|---|---|
| Switch output | J120: one SPDT; set point rising or falling; wired normally open or closed |
| Electrical rating (standard) | 15 A at 125/250/480 VAC; 2 A resistive and 1 A inductive at 24-30 VDC |
| Adjustable deadband models | 20 A at 125/250/480 VAC (selected model numbers) |
| Set point repeatability | Plus or minus 1% of full scale; 1.5% on some models; 0.5% on 450-457 and 550-559 |
| Enclosure | Die-cast aluminium, epoxy powder coated, gasketed, cover lock; Type 4X, IP66; Class I Div 1 meets Type 7 |
| Conduit connection | Two 3/4 NPT connections with terminal block (types J, C, F) |
| Ambient temperature | -58 to 160 degrees F (-50 to 71 degrees C) for most models; 0 to 160 degrees F (-17 to 71 degrees C) for listed models |
| Shock and vibration | Set point repeats after 15 g, 10 ms and 2.5 g, 5-500 Hz |
| Weight | About 4.5 lb for most J120 models; 5 lb, 6 lb or 8.5 lb for others, per the bulletin |
| Approvals as printed | UL: Class I Div 1 Groups B, C, D; Class II Groups E, F, G; Class III; Type 4X; ATEX II 2 G Ex db IIC T6 Gb and II 2 D Ex tb IIIC T85 degrees C Db, IP66; IECEx Ex db IIC T6 Gb |
| Ex ia option | Ex ia IIC T6 Ga, -50 to +60 degrees C, requires option M405 (includes PESO) |
| Regional options | M391 Brazil, M395 Korea, M404 Ukraine, M408 China, M406 EAC, M462 UK, M463 UAE (ECAS) |
Pressure models and sibling types
Model charts in the bulletin list each range with its adjustable set point, deadband, over range, proof pressure, wetted materials, port thread and sensor style. Examples are model 134 (30 inches Hg vacuum to 20 psi, brass, 1/4 NPT, 0.06 inch orifice), S134B (welded 316L stainless steel, 1/2 NPT) and 171 (1 to 20 psi, 316L stainless steel, over range 500 psi, proof 1000 psi). The same bulletin covers these related types:
| Type | Measures | Description |
|---|---|---|
| J120 | Pressure | One SPDT, internal adjustment, dual conduits |
| H121 / H122 | Pressure | One or two SPDT, external adjustment with reference dial, single conduit |
| J120K | Differential pressure | One SPDT, internal adjustment |
| H121K / H122K | Differential pressure | One or two SPDT, external dial |
| B121 / B122 / C120 | Temperature | Immersion stem |
| E121 / E122 / F120 | Temperature | Bulb and capillary |
Ordering and documents
The part number is built from type, model and options, for example J120-551-M201 in the bulletin. Please quote the full number, range, wetted material, approval option and quantity. Confirm the media compatibility, the set point on rising or falling pressure, the hazardous area marking required on site and whether an instrument siphon is needed when media temperature exceeds the ambient limits. Other United Electric switches on this site include the United Electric H100-172; related items are under Pressure Instrumentation. The attached United Electric 120 Series bulletin (120-B 15) holds the full model, option and dimension tables.
How the United Electric J120 works
The J120 senses pressure through a diaphragm or piston sensor at the process port. When pressure moves past the set point, the sensor moves a snap-action switch inside the enclosure, and the contacts change state. Because the switch is SPDT, it can be wired normally open or normally closed, and it works on a rising or falling signal. The set point is adjusted with a screw under the cover and locked in place. The gap between trip and reset is the deadband.
Where the United Electric J120 is used
- Pump and compressor protection
- Hydraulic and lube oil circuits
- Burner and boiler lines
- Oil and gas skids in hazardous areas
- Process alarm and shutdown loops
Selection checklist for the United Electric J120
- Pressure, vacuum or differential range
- Sensor style from A to K
- Wetted materials suited to the medium
- Proof pressure and over range
- Fixed or adjustable deadband
- Electrical load, AC or DC
- Area classification and marking
- Conduit and port thread
Installation, commissioning and maintenance notes for the J120
Fit the switch where it can be reached and where vibration is moderate. Connect the process port with a suitable fitting and a snubber if the line pulses. Remove the cover, wire the terminals and seal the conduit as the area rule requires. Set the trip point against a test gauge, lock the setting and refit the cover. Check the set point on a routine schedule.
Requesting a quotation for the United Electric J120
Please send the model code, the pressure range, the wetted material, the area classification and the quantity. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.
J120 electrical rating
The standard rating is 15 A at 125, 250 or 480 VAC. On DC it is 2 A resistive at 24 to 30 V.
J120 enclosure
The die-cast aluminium case is epoxy coated and gasketed, with two 3/4 NPT conduit entries. The data sheet gives Type 4X and IP66.
J120 temperature and weight
Most models operate from minus 50 to 71 degrees C. A typical unit weighs about 4.5 lb.
J120 repeatability
Set point repeatability is plus or minus 1 percent of full scale, with tighter figures on some models.
Switch records for the J120
Record the model code, the set point and the date of the last check.
Choosing the right J120 sensor
Choose the sensor style from the range and the medium, and keep normal pressure away from the range limit.
Datasheets & Documents
- Datasheet United Electric 120 Series bulletin (120-B 15) Download
Reviews (0)
About brand
United Electric Controls has made pressure and temperature switches since 1931 in Watertown, USA. Instrument technicians usually shorten the name to UE, which is also what appears on many nameplates.
Seven Star LLC lists United Electric pressure switches from the H100 family and the One Series and supplies them to plants in Oman for alarm and shutdown duties.
United Electric pressure switches listed here
Two kinds of UE switch are on this page:
- H100-172, H100-190, H100-361 and H100-376: electromechanical pressure switches from the 100 Series, which the manufacturer builds in a NEMA 4X enclosure. The number after the dash is the model that fixes the sensor type and the adjustable range.
- One Series 1XSWLL: an electronic pressure switch with a digital display, from UE's explosion-proof One Series.
An H100 switch needs no power to operate its contacts. A One Series unit is an electronic device, so its supply and output wiring must be considered when it replaces a mechanical switch.
Where United Electric switches are used
Pressure switches of this kind sit on pump discharge lines, compressor lube oil systems, burner trains, hydraulic units and process vessels. They raise an alarm or trip equipment when pressure moves outside a set limit. In oil and gas, power and water plants across the GCC they are found in alarm and shutdown circuits and on packaged equipment.
Ordering United Electric switches: what we need
A UE model is a string: the type, the model number and then option codes. Send it complete, exactly as on the nameplate, for example H100-190 plus any option codes that follow. If the nameplate is unreadable, give us the adjustable range, the set point and whether it acts on rising or falling pressure, the process connection, the wetted material, the switch output and the enclosure or hazardous-area requirement. For the One Series, the full 1XSWLL code with its range and option suffixes is needed. We check each code against the manufacturer documentation and propose the manufacturer's successor if a model is no longer built.
Browse United Electric controls products by category: Pressure Instrumentation.
Related products
Frequently Asked Questions
Is the J120 internally or externally adjusted?
Internally, with an internal set point lock; the H121 and H122 types use an external dial.
What switch output does it have?
One SPDT switch, wired normally open or closed, at 15 A rating on standard models.
What enclosure rating is stated?
Type 4X and IP66; the Class I Division 1 product meets Type 7.
Which hazardous-area marking is listed?
ATEX II 2 G Ex db IIC T6 Gb and IECEx Ex db IIC T6 Gb, plus UL Class I Div 1 Groups B, C, D.
Is an intrinsically safe version available?
Yes, Ex ia IIC T6 Ga, but option M405 must be ordered for that certification.
Reviews
There are no reviews yet.