Embraco EMY 3111 Z Refrigerator Compressor – R134a, LBP, 1/8 HP, 4.53 cm³, 127 W

Embraco EMY 3111 Z is a hermetic reciprocating compressor running on R134a. It is designed for LBP (low back pressure) operation and is used in freezers, deep freezer cabinets, frozen product display cabinets and small refrigeration circuits operating at low temperatures.

1/8 HP Hermetic Compressor for Freezer and Low-Temperature Applications

With a displacement of 4.53 cm³, it is in the 1/8 HP class and delivers a cooling capacity of approximately 127 W at the ASHRAE LBP condition (−23.3 / +54.4 °C). It is optimized to maintain its efficiency at low evaporating temperatures — unlike MBP/HBP models, LBP compressors operate stably at evaporating temperatures of −20 °C and below.

It uses an RSIR starting arrangement (resistance start, no capacitor) with a PTC starting device and an overload protector. This arrangement is for capillary tube systems: because circuit pressures equalize during standstill, the compressor can start with low starting torque. It is preferred in circuits that use a capillary tube as the expansion device; systems with a thermostatic expansion valve (non-equalizing) require a model with CSIR/RSCR starting.

Technical Specifications

• Model: Embraco EMY 3111 Z (EMY3111Z)
• Type: Hermetic reciprocating compressor
• Refrigerant: R134a
• Operating Range: LBP — low back pressure (freezer)
• Displacement: 4.53 cm³ | Motor Class: 1/8 HP
• Cooling Capacity: 127 W (ASHRAE LBP, −23.3 / +54.4 °C)
• Power Supply: 220-240 V / 50 Hz, single phase | Starting: RSIR + PTC starting device
• Current: Running 0.64 A | Starting (LRA): 5.0 A
• Expansion Device: Capillary tube — for equalizing circuits
• Oil: Ester (POE), approx. 150 ml — factory charged
• Dimensions: Width 228 mm · Depth 163/155 mm · Height 171 mm | Weight: 7.7 kg
• Base Plate: 200 × 178 mm, mounting hole Ø16 mm (×6) — EM series European base
• Tube Connections: Suction Ø6.1-6.2 · Service Ø5.9-6.2 · Discharge Ø4.9-5.2 mm copper
• Images: dimension drawing in the 2nd image, electrical wiring diagram in the 3rd image

Capacity Curve (CECOMAF EN12900)

Cooling capacity varies with evaporating temperature:

• −10 °C → 237 W  ·  −20 °C → 165 W  ·  −25 °C → 123 W  ·  −30 °C → 90 W

• ⚙️ The HP value is the motor class, not the capacity. Base your selection on the cabinet heat load and the target evaporating temperature; the curve above is for that purpose.
• 🔧 For capillary tube circuits. If an RSIR compressor is forced to restart before the pressures have equalized, it cannot start and the overload protector trips.
• POE oil absorbs moisture: Do not leave the circuit open, evacuate before installation and always replace the filter drier.
• When the PTC starting device is hot, wait 3-5 minutes before restarting — do not attempt repeated starts.