Application Engineering |
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B U L L E | T | I | N |
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Retrofit Applications To Avoid
NOTICE
Always check with the original equipment manufacturer, before modifying the equipment, to understand their warranty policies regarding equipment modifications.
The success of the retrofit will depend on the amount of planning and evaluation done before the retrofit. Applications such as clean rooms for manufacturing sensitive components, laboratories, hospital operating and recovery rooms, and equipment rooms that require constant cooling are all applications that would benefit from a modulating digital scroll. Many of these are critical cooling applications and require equipment that is designed specifically for these applications. Don’t attempt to retrofit a
Applications that have complex refrigeration circuits (modulating reheat, heat recovery for water heating, etc.) should not be considered for a digital scroll retrofit.
Performance Modeling
NOTICE
Emerson Climate Technologies, Inc. is not responsible or liable for incorrect energy use predictions.
Successful digital scroll retrofit projects, and resultant energy savings, have been documented by several industry energy groups. Predicting the energy usage and calculating a return on investment before the project is undertaken is not trivial and is best done by experienced companies that use advanced software programs to predict energy use. Before large retrofit projects are considered, as much
System Modifications
NOTICE
Always check with the OEM of the equipment being considered for the digital scroll retrofit, before the retrofit is undertaken. The OEM may
have specific instructions developed that offer step by step guidance.
Before beginning the retrofit, the system should be operable and system operating conditions should be logged for future reference. The compressor suction
&discharge pressures, suction superheat, subcooling, volts, amps, evaporator air flow and leaving temperature, and system charge should all be measured and recorded prior to any system modifications.
Compressor Selection & Change-Out
The replacement digital scroll compressor should be compared to the
1.Performance – the full load capacity of the digital scroll should be approximately equal to the capacity of the compressor being replaced. In some cases in might make sense to “right size” the compressor capacity for the load if the compressor is grossly oversized.
2.Electrical – the digital scroll compressor RLA and LRA should be compared to the compressor being replaced. Contactor, wire, breaker/fuse, and run capacitor sizes should be evaluated.
3.Mechanical – in most cases the compressor mounting will be identical for the
The following steps should be followed to remove the
1.Using an EPA approved refrigerant recovery machine, recover the system refrigerant charge from the low and high sides of the system.
2.Disconnect and lockout the power supply. Confirm that all voltage sources have been disconnected by using a voltmeter. Disconnect the conduits and wiring to the compressor and move them out of the way as much as possible.
3.By using manifold gauges, verify that the system refrigerant charge is completely recovered from the system. Suction and discharge pressures must be 0 psig.
4.Using a tubing cutter, cut the suction and discharge lines close to the compressor.
5.Remove the compressor mounting bolts.
6.Plug the compressor suction and discharge connections to prevent the spillage of oil from the compressor when removing it from the system.
© 2012 Emerson Climate Technologies, Inc. | 8 |
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