IMP120-14
www.ueonline.com
120 Series
Explosion-Proof Pressure and
Differential Pressure Switches
Types
J120, J120K, H121, H121K, H122,
H122K, H122P
U N I T E D E L E C T R I C
C O N T R O L S
Installation and Maintenance
Instructions
IMP120-14
which convert the pressure signal into an electrical signal. Control
set point(s) may be varied by turning the internal adjustment hex
(J120 models) or the external knob and pointer(s) (H121, H122, H122P
models) according to the procedures outlined.
Please refer to product bulletin for product specifications. Product
bulletins may be found at www.ueonline.com.
Date code format on nameplate is “YYWW” for year and week.
Part I -Installation
Tools Needed
–Screwdriver/Adjustable Wrench to 1-1/2”
MOUNTING
THe ConneCTIon of THe DevICe SHAll be MADe bY
CAble enTrIeS or A SToPPIng box CerTIfIeD In TYPe
of exPloSIon ProTeCTIon flAMeProof enCloSure ‘d,’
SuITAble for THe ConDITIonS of uSe AnD CorreCTlY InSTAlleD.
THeSe ACCeSSorIeS SHAll be THreADeD InTo THe relevAnT
oPenIng(S) of THe DevICe, WITH AT leAST 5 THreADS engAgeD
AnD WITH AT leAST 8 mm lengTH of THreAD engAgeMenT. THeSe
ACCeSSorIeS Are noT InCluDeD WITHIn THe DevICe’S HAzArDouS
loCATIonS CerTIfICATe.
To PrevenT IgnITIon, SeAl All ConDuIT runS WITHIn 18
InCHeS of enCloSure.
AlWAYS HolD A WrenCH on THe PreSSure HouSIng Hex
WHen MounTIng unIT. Do noT TIgHTen bY TurnIng
enCloSure. THIS WIll DAMAge SenSor AnD WeAken
SolDer or WelDeD JoInTS.
InSTAll unITS WHere SHoCk, vIbrATIon AnD TeMPerATure
fluCTuATIonS Are MInIMAl. MounT unIT To PrevenT
MoISTure froM enTerIng THe enCloSure. IT IS
IMPerATIve To uSe ProPerlY rATeD exPloSIon-Proof SeAlIng
fITTIngS for eleCTrICAl WIre enTrY. Do noT MounT unIT
In AMbIenT TeMPerATureS THAT exCeeD THe lIMITS on THe
nAMePlATe for THe APProPrIATe AreA.
J120 enCloSureS Are ProvIDeD WITH TWo 3/4” nPT
eleCTrICAl ConDuIT oPenIngS, eITHer of WHICH or boTH
CAn be uSeD DurIng InSTAllATIon. A 3/4” exPloSIon
Proof Plug IS ProvIDeD for ProPerlY SeAlIng THe unuSeD
ConDuIT oPenIng. THe exPloSIon Proof Plug MuST be
ProPerlY SeAleD DurIng ProDuCT InSTAllATIon.
GENERAL
MISuSe of THIS ProDuCT MAY CAuSe exPloSIon AnD
PerSonAl InJurY. THeSe InSTruCTIonS MuST be
THorougHlY reAD AnD unDerSTooD before unIT IS
InSTAlleD.
THIS equIPMenT IS SuITAble for uSe In ClASS I, DIvISIon
1, grouPS b, C AnD D; ClASS II, DIvISIon 1, grouPS e, f
AnD g; ClASS III; or non-HAzArDouS loCATIonS onlY.
enCloSure TYPe 4x.
THIS equIPMenT IS ATex CerTIfIeD for equIPMenT
CATegorY 2. SuITAble for APProPrIATe uSe In gAS zone
1 & DuST zone 21 APPlICATIonS.
0539 DeMko 09 ATex 0815573x
II 2 g ex d IIC T6
II 2 D ex tD A21 IP66 T+ 85°C
-40°C ≤ Tamb. ≤ + 75°C
before InSTAllIng, CHeCk THe SenSor MoDel SeleCTeD
for CoMPATIbIlITY To THe ProCeSS MeDIA In ConTACT
WITH THe SenSor AnD WeTTeD PArTS.
Proof PreSSure* lIMITS STATeD In THe lITerATure AnD
on nAMePlATeS MuST never be exCeeDeD, even bY
SurgeS In THe SYSTeM. oCCASIonAl oPerATIon of unIT
uP To MAxIMuM PreSSure IS ACCePTAble (e.g., STArT-uP, TeSTIng).
ConTInuouS oPerATIon SHoulD noT exCeeD THe DeSIgnATeD
over rAnge PreSSure.
*Proof Pressure: The maximum pressure to which a pressure sensor
may be occasionally subjected, which causes no permanent damage
(e.g., start-up testing). The unit may require re-gapping. (See Part
II- Adjustments)
THeSe ProDuCTS Do noT HAve AnY fIelD rePlACeAble
PArTS. AnY SubSTITuTIon of CoMPonenTS MAY IMPAIr
SuITAbIlITY for ClASS I, DIvISIon 1.
To PrevenT IgnITIon of HAzArDouS ATMoSPHereS,
DISConneCT SuPPlY CIrCuITS before oPenIng. keeP
Cover TIgHT WHIle CIrCuITS AlIve.
The 120 Series pressure and differential pressure switches are
actuated when a bellows, diaphragm or piston sensor responds to
a pressure change. This response at a pre-determined set point(s)
actuates a SPDT, DPDT or dual SPDT snap-acting microswitch(es),
Please read all instructional literature carefully and thoroughly before starting. Refer to the final page for the listing of Recommended
Practices, Liabilities and Warranties.
