Leak detection
•
Never pressurize the refrigeration system with oxygen or dry air. This could cause fire or explosion.
•
Do not use leak detection dye.
•
Perform a leak detection test on the complete system.
•
The low side test pressure must not exceed 450 psig.
•
When a leak is discovered, repair the leak and repeat the leak detection.
Vacuum dehydration
•
Never use the compressor to evacuate the system.
•
Connect a vacuum pump to both the LP & HP sides.
•
Pull down the system under a vacuum of 500 microns Hg.
•
Do not use a megohmmeter nor apply power to the compressor while it is under vacuum as this may cause damage.
Electrical connections
•
Switch off and isolate the main power supply.
•
All electrical components must be selected as per local standards and compressor requirements.
•
Refer to page 4 for electrical connections details. Three-phase applications, the terminals are labeled T1, T2, and T3.
•
Tecumseh scroll compressors will only compress gas while rotating counter-clockwise (when viewed from the
compressor top). Three-phase motors will start and run in either direction, depending on the phase angles
of the supplied power. Care must be taken during installation to ensure that the compressor operates in the correct
direction.
•
Use #10 - 32 screws and ¼” ring terminals for the power connection with ring connect screw terminal (C type).
Fasten with 26.6 in. lb torque.
•
Use a self tapping screw to connect the compressor to ground.
Charging the system
•
Keep the compressor switched off.
•
Keep the refrigerant charge below the indicated charge limits if possible.
Above this limit; protect the compressor against liquid flood-back by using
a pump-down cycle or suction line accumulator.
•
Never leave the filling refrigerant cylinder connected to the circuit.
Verification before commissioning
Use safety devices such as safety pressure switch and mechanical relief valve in compliance with both generally and
locally applicable regulations and safety standards. Ensure that they are operational and properly set.
•
Check that the settings of high-pressure switches don’t exceed the maximum
service pressure of any system component.
•
A low-pressure switch is recommended to avoid low pressure operation.
(Please refer to the Minimum Setting table to the right).
•
Verify that all electrical connections are properly fastened and in compliance
with local regulations.
•
When a crankcase heater is required, it must be energized at least 24 hours
before initial start-up and start-up after prolonged shutdown.
Startup
•
Never start the compressor without the proper refrigerant charge.
•
Do not provide electrical power to the compresor unless suction and discharge service valves are open, if installed.
•
Energize the compressor. It must start promptly. If the compressor does not start, check wiring conformity and
voltage at the compressor terminals.
•
Reverse rotation can be detected by following phenomena; excessive noise, no pressure differential
between suction and discharge, and line warming rather than immediate cooling. A service technician should be
present at initial start-up to verify that supply power is properly phased and that the compressor is rotating in the
correct direction. Phase monitors are required for all applilcations.
•
If the internal overload protector trips out, it must cool down to 140°F (60°C) to reset. Depending on ambient
temperature, this may take up to several hours.
©2014 Tecumseh Products Company. All Rights Reserved.
Check with running compressor
•
Check current draw and voltage. Measurement of amps and volts during running conditions must be taken at other
points in the power supply, not in the compressor electrical box.
•
Check suction superheat to reduce risk of slugging.
•
Observe the oil level in the sight glass (if provided) for about 60 minutes to ensure proper oil return to the compressor
•
Respect the operating limits.
•
Check all tubes for abnormal vibration. Movements in excess of 1/16 in (1.5 mm) require corrective measures such as
tube brackets.
•
When needed, additional refrigerant in liquid phase may be added in the low-pressure side as far as possible from the
compressor. The compressor must be operating during this process.
•
Do not overcharge the system.
•
Never release refrigerant to the atmosphere.
•
Before leaving the installation site, carry out a general installation inspection regarding cleanliness, noise and leak
detection.
•
Record type and amount of refrigerant charge as well as operating conditions as a reference for future inspections.
Maintenance
Internal pressure and surface temperature are dangerous and may cause permanent injury. Maintenance operators and
installers require appropriate skills and tools. Tubing temperature may exceed 212°F (100°C) and can cause severe burns.
Ensure that periodic service inspections to ensure system reliability and as required by local regulations are performed.
To prevent system related compressor problems, following periodic maintenance is recommended:
•
Verify that safety devices are operational and properly set.
•
Ensure that the system is leak tight.
•
Check the compressor current draw.
•
Respect the operating limits.
•
Confirm that the system is operating in a way consistent with previous maintenance records and ambient conditions.
•
Check that all electrical connections are still adequately fastened.
•
Keep the compressor clean and verify the absence of rust and oxidation on the compressor shell, tubes and electrical
connections.
•
Acid / moisture content in system and oil should be checked regularly.
Warranty
Always provide the model number and serial number with any product warranty claim
The product warranty may be void in the following cases:
•
Absence of compressor nameplate/label.
•
External modifications; in particular, drilling, welding, broken feet and shock marks.
•
Compressor opened or returned unsealed.
•
Rust, water or leak detection dye inside the compressor. Do not overcharge the system.
•
Use of a refrigerant or lubricant not approved by Tecumseh.
•
Any deviation from recommended instructions pertaining to installation, application or maintenance.
•
Use in mobile applications.
•
Use in explosive atmospheric environment.
•
No model number or serial number transmitted with the warranty claim.
Disposal
Tecumseh recommends that compressors and compressor oil should be recycled by a suitable company at its site.
QuESTIoNS AND SuppoRT
Tecumseh Tech Support: 800.211.3427 or Email: [email protected]
Tecumseh reserves the right to change any information in this publication at any time.
This document is not intended to replace the training required for professional service personnel, or replace other information available from
refrigeration and air conditioning equipment manufacturers. The information in this document is intended to assist service personnel in safely
installing and servicing Tecumseh VSC Series Scroll compressors. Careful review of current application requirements is essential. IT IS THE
RESPONSIBILITY OF THE SERVICE PERSON TO ASSURE THEY HAVE PURCHASED A REPLACEMENT PRODUCT WHICH MEETS THE NEEDS
OF THE APPLICATION. Failure to do so may result in misapplication, requiring immediate or subsequent additional compressor replacement(s).
Minimum Settings
R22
7 psig
R134a
6 psig
R404A
20 psig
HP
Refrigerant
charge limit (lb)
4 - 6
10
8 - 10
16
