Schreiber Chillers 15MEDAC email - Manual (Page 51)

Ignition cannot occur at the venting terminal without the presence of contaminant air, and cannot occur
externally from the venting terminal without the presence of an external ignition source.
It is, therefore, essential that any air in a refrigeration, air conditioning, or heat pump system be
completely removed when the system is manufactured – when the system is installed – and whenever the
system is field processed a result of field service. Field service includes, but is not limited to, leak repairs
or compressor replacement.
Eliminating air within the system prevents ignition at, or in, the hermetic compressor if a terminal should
vent, thereby reducing the hazard potential.
To reduce the possibility of external ignition, all open flame, electrical power, and other heat sources
should be extinguished or turned off prior to servicing a system.
Before using a soldering or welding torch to remove or repair tubing, make sure all the system refrigerant
charge has safely been released
A venting terminal presents no danger to servicing personnel or anyone else in the vicinity if the
compressor terminal PROTECTIVE COVER is properly in place as shown on Tecumseh Products
Company drawings and diagrams using the parts as shown on Tecumseh Products Company bills of
material.
Hermetic compressors can be properly serviced without unnecessarily removing the terminal
PROTECTIVE COVER by adhering to the following service procedures:
1. If the branch circuit, short circuit, and ground fault protective device, i.e., fuse or the circuit
breaker is open, this is a strong indication that an electrical problem exists and must be found and
corrected.
The circuit protective device rating must first be checked as required by the National
Electrical Code, and its maximum rating should coincide with that marked on the equipment
nameplate and/or on the unit wiring diagram and/or instructions. This beaker or fuse rating
should be as low as practical. A rule of thumb is 175% times the motor-compressor RLA
(FLA on older units) as shown on the unit nameplate.
It is acceptable to first replace the fuse or reset the circuit breaker ONE TIME to determine if it
was just a nuisance opening. WARNING! The terminal PROTECTIVE COVER must be securely
in place.
2. If the fuse or circuit breaker again opens, DO NOT continue to replace or reset, as the equipment
obviously has an electrical problem. CAUTION! Continual resetting may cause the terminal to
vent.
3. DISCONNECT all power to the unit, making sure all power legs are open.
4. Without removing the terminal PROTECTIVE COVER, disconnect the three leads going to the
compressor terminals at the nearest point to the compressor, and identify them as Common (C),
Start (S), and Run (R). Identification can generally be made through the unit- wiring diagram.
DO NOT disconnect at the compressor terminals at this time.