This document describes the Nash_elmo G_400 series gas-ring vacuum pumps/compressors, including models 2BH7 2, 2BH7 3, 2BH7 4, 2BH7 5, and 2BH7 6. It covers transport, installation, commissioning, operation, shut-down, storage, servicing, and disposal. The manual emphasizes safety precautions and proper handling to prevent injuries or damage to the unit.
Function Description
The G_400 series units are pump-motor units designed to generate vacuum or gauge pressure. They are primarily used to extract, pump, and compress non-flammable, non-aggressive, non-toxic, and non-explosive gases or gas-air mixtures, such as air, in industrial applications. These units are designed for continuous operation, though increased switch-on frequency or elevated ambient temperatures may require consultation with the Service Department to prevent exceeding winding and bearing temperature limits.
The G_400 series is available in three main designs:
- Single-impeller (single-stage) models: These units feature a single impeller for single-stage operation.
- Two-impeller (two-stage) models: These units incorporate two impellers, allowing for two-stage operation and achieving increased pressure differences.
- Three-impeller (three-stage) models: These units utilize three impellers for three-stage operation, providing the highest pressure differences among the series.
Drive motors for these units can be either 3-phase AC drive motors with a standard or explosion-protected design, or single-phase AC drive motors. This manual specifically applies to pump-motor units with a standard design; separate operating instructions are provided for explosion-protected designs.
Important Technical Specifications
Weight:
- Single-impeller models: Range from approximately 16 kg (35.3 lbs) for 2BH7210-0..1.- to 35 kg (77.2 lbs) for 2BH7610-0..3.-.
- Two-impeller models: Range from approximately 24 kg (52.9 lbs) for 2BH7220-0..2.- to 65 kg (143 lbs) for 2BH7620-0..5.-.
- Three-impeller models: The 2BH7630-0..6.- model weighs approximately 94 kg (207 lbs).
Minimum Distances:
- Minimum distance to vacuum pump/compressor cover: 30 mm (1.18 inches).
- Minimum distance to fan guard (for sucking in cooling air): Ranges from approximately 34 mm (1.34 inches) for 2BH72/73 to 53 mm (2.09 inches) for 2BH76.
Vibrations:
- Maximum permissible vibration path (S): ≤ 0.16 mm (≤ 0.006 inches).
- Maximum permissible vibration velocity (Veff): ≤ 4.5 mm/s (≤ 0.015 ft/s).
- Maximum permissible vibration acceleration (a): ≤ 2.55 m/s² (≤ 8.37 ft/s²).
Noise Level (1-m measuring-surface sound pressure level L [dB(A)]):
- Single-impeller models: At 50 Hz, range from approx. 57 dB(A) to 65 dB(A). At 60 Hz, range from approx. 62 dB(A) to 71 dB(A).
- Two-impeller models: At 50 Hz, range from approx. 58 dB(A) to 68 dB(A). At 60 Hz, range from approx. 62 dB(A) to 72 dB(A).
- Three-impeller models (2BH7630-0..6.-): Approx. 77 dB(A) at 50 Hz and approx. 80 dB(A) at 60 Hz.
Temperature Increase (ΔT [K] / Δ9 [F]):
- These values indicate the heating of pump/compressor housings and exiting air compared to ambient temperature during operation at permissible total pressure difference and air pressure of 1,013 mbar (14.7 psi). Lower air pressures increase these values.
- Single-impeller models (50 Hz): ΔT ranges from approx. 52 K (126 °F) to 124 K (255 °F).
- Single-impeller models (60 Hz): ΔT ranges from approx. 61 K (142 °F) to 124 K (255 °F).
- Two-impeller models (50 Hz): ΔT ranges from approx. 55 K (131 °F) to 125 K (257 °F).
- Two-impeller models (60 Hz): ΔT ranges from approx. 77 K (171 °F) to 128 K (262 °F).
- Three-impeller models (50 Hz & 60 Hz): ΔT is approx. 120 K (248 °F).
Operating Conditions:
- Temperature: Max. permissible temperature of +40 °C (104 °F) for the unit and ambient. Min. permissible ambient temperature is -30 °C (-22 °F). Nominal values are +15 °C (59 °F) for the unit and +25 °C (77 °F) for ambient.
- Pressure: Minimum inlet pressure and maximum discharge pressure during compressor operation are specified on the rating plate. Max. permissible pressure in the pump-motor unit is 2.5 bar abs. (36.2 psia). A pressure relief valve may be necessary.
- Installation Altitude: Max. 1,000 m (3,280 ft) above sea level. Inquire with Service Department for higher altitudes.
Usage Features
Installation:
- The pump-motor unit should be installed on a solid foundation or mounting surface to prevent balance damage from vibrations.
- It can be installed in dusty or damp environments, in buildings, or in the open (with protection from intensive sunlight).
- Minimum distances to the fan guard and pump/compressor cover must be maintained for adequate cooling.
- Horizontal installation: The base of the unit should be screwed to the surface using suitable mounting elements.
- Vertical installation (cover installation): For vertical installation with the vacuum pump/compressor cover facing downward, rubber feet (available as accessories) must be used and secured to the installation surface.
- Vertical mounting on the wall: The unit is mounted via holes in the base to a stable supporting plate.
- Noise reduction: Mufflers are included as standard equipment. Additional mufflers and noise protection hoods are available as options for further noise reduction.
- Electrical connection: Must be carried out by trained electricians according to national/local laws and regulations. The motor circuit breaker must be adjusted to the specified nominal current.
- Pipe/hose connections: Pumped gases are sucked in via the inlet connection (with muffler) and discharged via the discharge connection (with muffler). Flow direction arrows are marked on connections and the fan guard. Sealing plugs must be removed immediately before connecting pipes/hoses. Filters should be installed in the inlet pipe to prevent solid bodies from entering the unit.
Operation:
- Before start-up, ensure the unit is completely assembled, pipes/hoses are properly connected, and connections are not closed, clogged, or soiled.
- The motor circuit breaker must be adjusted to the drive-motor nominal current.
- Check the direction of rotation by briefly switching the unit on and off, comparing the external fan's rotation with the marked arrows. Reverse motor direction if necessary.
- Observe the operating speed specified on the rating plate to avoid damage and excessive noise/vibration.
- During operation, avoid touching hot surfaces (up to 160 °C / 320 °F).
- For drive motors with closed condensed water openings, remove closures occasionally to drain collected water to prevent rusting.
Maintenance Features
Servicing:
- All maintenance work must be performed by the Service Department or by the operator if a related maintenance manual is available.
- Regularly check mounting elements, connections, lines, fittings, and containers for strength, leaks, and firm seating.
- Regularly replace filters in the inlet pipe.
- If the unit has come into contact with dangerous substances, it must be decontaminated before being sent for service. A "Declaration of Clearance" form is required.
Shut-Down and Longer Standstills:
- Switch off the pump-motor unit, close shut-off devices in intake/pressure lines, and disconnect from power supply.
- Release pressure slowly and carefully from pipes/hoses.
- Remove pipes/hoses and provide mufflers with sealing plugs.
- Avoid heavy mechanical impacts during standstill.
Storage Conditions:
- Store in a dry, dust-free, low-vibration environment with an ambient temperature of max. 40 °C (104 °F).
- Lubrication of rolling bearings: If storage time exceeds certain periods (4 years under advantageous conditions, 2 years under disadvantageous conditions like high humidity or dusty air), the rolling bearings must be re-lubricated or replaced. Inquire with the Service Department for specific procedures and grease types.
Repairs/Troubleshooting:
- The manual provides a troubleshooting guide for common issues such as the motor not starting, protective motor switch trips, high power consumption, or insufficient pressure difference.
- Remedies include checking power supply, clearing jammed impellers, replacing defective impellers or bearings, checking windings, reducing throttling, cleaning filters/mufflers, sealing leaks, correcting rotation direction, and adjusting frequency.
- Most repairs require a trained electrician or Service Department intervention.
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