Emerson OMB - User Manual

FEATURES
• Self contained unit with oil level sensor and integral solenoid to
manage oil level supply
• Hall-effect sensor for precise measurement of oil level
• Alarm and status indication by LEDs
• SPDT output contact for compressor shutdown or alarming
• Easy installation by sightglass replacement
• Adapters suitable for various types of compressors including
conventional and scroll compressors
• Signalgeneratedbygravitybasedoat–notpronetoerrorsfrom
foaming like optical sensors
• Sacricialmagnetforreliableoperation
SAFETY INSTRUCTIONS
WARNING: Before opening any system, make sure the pressure in the
system is brought to and remains at atmospheric pressure. Failure to
comply can result in personal injury and/or system damage.
WARNING: The OMB/C operates by using a strong magnetic sensor. It
is important to keep the control free of any steel or iron particles which
could accumulate on it during installation. These may hamper or prevent
the control from operating.
1. Read installation instructions thoroughly. Failure to follow instructions
may result in product failure, system damage, or personal injury.
2. Do not open system under pressure.
3. EnsuresupplyvoltageiswithinspeciedOMB/Climits.
4. Disconnect supply voltage from system/OMB/C before installation/
service. Comply with local electrical regulations when wiring OMB/C.
5. Do not exceed maximum working pressure.
6. Keep temperature within nominal limits.
7. Workshouldbeperformedbyqualiedservicepersonneloralicensed
contractor.
INSTALLATION INSTRUCTIONS
1. Read installation instructions thoroughly.
2. Assure that you have the appropriate mounting adapter kit for the
compressor. See adapter kit instruction sheet (PA-00316) for choosing
proper adapter and installation instructions.
3. O-ring replacement kit (KS30368) can be used on the OMB, OMC and
W-OLC controls.
4. If replacement of OMB or OMC is required, replace like for like
OMB/C Oil Management Control
Instruction Sheet
PA-00388
INSTRUCTIONS FOR FIELD CHANGEOUT OF
OMB OR OMC OIL CONTROL
This instruction has been developed to minimize down time based
uponactualeldexperience.Readthroughtheentireinstructionbefore
proceeding with the change-out.
Tools Recommended: 7/16" nut driver; 7/16" open-end wrench;
adjustable wrench; slotted screwdriver; wire stripper; manifold
gauge set; refrigeration valve wrench (Additional items which may be
required depending on application: 1' of ¼" refrigerant grade copper
tubing.2-¼"brassarenuts;aringtool;3/8"maleareby¼"female
areadapter;3-electricalwirenuts).
1. Disconnect all electrical power to the compressor.
2. Safely connect gauge bar hoses in the following sequence: discharge
line to backseat port of an adjacent compressor service valve;
common line to oil pressure port on crankcase of compressor on
which control is to be changed; suction line to suction manifold on
compressor rack. (Manifold valves should be closed.)
3. Close discharge, suction, and oil feed service valves on compressor.
4. Open the gauge manifold discharge hand wheel to pressurize the
crankcase to discharge pressure. (Important: Do not exceed
allowable pressure limits set by the compressor manufacturer
for the crankcase.)
5. After pressurizing the crankcase to a safe pressure, close manifold
gage discharge wheel.
6. Open the gage manifold suction wheel to allow the high pressure in
the crankcase to meter the oil into the suction manifold.
7. After the oil is below the sight glass on the compressor crankcase,
close the suction hand wheel and safely reclaim the remaining
refrigerant pressure in the crankcase.
8. After all the pressure is depleted in the crankcase, remove the existing
oil control as follows:
A. Disconnect the electrical leads at the control and label each if wire
color codes change.
 B. Removeexibleconduit(ifused)atthejunctionbox.
C. Disconnect the oil supply line. Note: A new one may need to be
fabricated, or an adapter required, if replacing an OMB with an OMC.
 D.Removetheangemountingboltswhichholdthecontroltothe
adapter and remove existing control.
OMC
SPECIFICATIONS OMB OMC OMC NH
3
OMC CO
2
Maximum Working Pressure (MWP) 870 psig 1885 psig
Solenoid min/max OPD 0/350 psig 0/1450 psig
Supply Voltage 24V, 50/60 Hz
120V, 220-240V,
50/60 Hz
24V, 120V, 220-240V
50/60Hz
Solenoid Coil EMF
Current Consumption 0.6 Amp (24V)
0.15 Amp (120V),
0.07 Amp (220-240V)
0.6 Amp (24V), 0.15 Amp
(120V), 0.07 Amp (220-240V)
Time Delay for Low Level Signal 10 seconds
Time Delay After Setpoint Recovery 5 seconds
Alarm Delay Time (Including Alarm Contact) 120 seconds
Alarm Switch SPDT
Alarm Contact Rating 10A @ 120VAC 50/60 Hz, 5A @ 250VAC 50/60 Hz, 3A @ 30VDC
Refrigerant Compatibility Class A1 (incl. subcritical CO
2)
Ammonia
Transcritical
CO
2
Refrigerant Temperature -40° to 180°F Maximum
Ambient Temperature - Storage -40° to 120°F Maximum
Ambient Temperature - Intermittent Duty -40° to 120°F Maximum
Oil Supply Fitting
1/4" Male SAE
(Brass)
(Stainless
Steel)
(Brass)

Emerson OMB Specifications

General

Brand	Emerson
Model	OMB
Category	Control Unit
Language	English

Summary

Product Features

Safety Instructions

Specifications

Field Changeout Procedure

Installation Instructions

LED Status Indicators

Green LED

Indicates power is supplied to the OMB/C control unit.

Yellow LED

Indicates oil level below sight glass for 10 seconds, fill solenoid activated.

Red LED (Continually Lit)

Oil level consistently low for over 2 mins, alarm activated, compressor prevented from operating.

Red LED (Flashing)

Five auto-reset alarms registered in 30 mins, alarm locked, compressor off.