Safety

EPA 608 Type 3 Chapter 12 (Take full course for free)

In this module, we will learn about a few safety practices that need to be kept in mind while dealing with EPA Type-3 appliances. Skip to quiz!

1. Basic Safety Precautions

Always remember that whenever working with refrigerants, always make sure that you are wearing proper personal protective equipment (PPE), including

• Safety glasses

• Safety gloves

• Safety shoes

• Safety hat/helmet

2. ASHRAE Standard 15

ASHRAE Standard 15 talks about the safety of persons and property on or near the premises where refrigeration facilities are located. For us, the important part to understand in this standard is the ‘Equipment Room Requirements.’

Recall that refrigerants are toxic, and inhaling them is life-threatening. When refrigeration equipment is kept indoors, a separate room is required for them. Any equipment room must have electronic refrigerant detectors and a mechanical ventilation system running continuously.

These systems pull the outside fresh air into the equipment room from one side and exhaust the room air from the other using mechanical fans and blowers. Compare this to a kitchen exhaust fan but much larger in size.

Equipment room refrigerant detectors are electronic detectors that sense refrigerants in the air and give out an alarm. Along with the alarm, the ventilation systems also turn on and start blowing in fresh air into the room. Any traces of refrigerant outside the system indicates a refrigerant leak.

Equipment room refrigerant detectors are also referred to as room sensors in the EPA exam. These sensors are compulsory in all equipment rooms having Type 3 appliances regardless of the refrigerant type.

The alarm will sound just before the TLV-TWA (Threshold Limit Value – Time Weighted Average) is crossed. Any refrigerant amount detected in the air above the TLV of the detector is harmful and sets off the alarm.

TWA is the average refrigerant limit for a normal 8-hour workday and a 40-hour workweek to which any person may be exposed every day without harmful effects. Throughout the day and week, the average refrigerant leak should not exceed the TWA values.

3. Best Practices

Recall that sight glass is a transparent glass used to check for signs of moisture inside a system. Ice or dirt may form on this sight glass at low temperatures that should be cleaned using an isopropyl alcohol spray. Isopropyl alcohol is also commonly used to de-ice car windshields during winters.

Recall that a rupture disc is a safety device set to burst open at a pressure of 15 psig. The discharge from the rupture disc should be vented outdoors in the atmosphere. This is done to prevent the accumulation of refrigerant in the equipment room in case of accidents.

4. Pressure Relief Valve

Recall that a relief valve protects against high pressures in the system. A daily example of this might be the 'Pressure cooker' and how the cap on top of the cooker lifts to release the pressurized steam inside it.

Boilers and compressor systems in the past have reported blasts due to pressures exceeding the allowable pressure for the system. A pressure relief valve is by far the most important safety component. A pressure relief valve must protect every refrigerating system.

Multiple pressure relief valve should never be installed in series to the system lines. This is because installing multiple valves makes all other valves useless as all pressure is released out of a single valve. Also, it may result in excessive loss of the fluid due to multiple valves releasing pressure at the same time.

5. Conclusion

In this module, we discussed the safety practices that need to be kept in mind while dealing with EPA Type-3 appliances. These practices are critical while performing any repair and maintenance works in any system.

Question #1: ASHRAE Standard 15-2013 requires which equipment to detect refrigerant leaks?

1. Room Sensors

2. Mechanical Ventilators

3. Pollution Detectors

4. Air purifiers with HEPA filters

Scroll down for the answer...

Room Sensors

As per ASHRAE Standard 15-2013, any equipment room must have electronic refrigerant detectors and a mechanical ventilation system running continuously.

However, to detect a refrigerant leak, electronic refrigerant detectors also known as room sensors are used.

Question #2: ASHRAE Standard 15-2013 requires the use of room sensors and alarms to detect refrigerant leaks of;

1. A1 refrigerants.

2. B2 refrigerants.

3. A2 refrigerants.

4. all refrigerant safety groups.

Scroll down for the answer...

all refrigerant safety groups.

ASHRAE Standard 15-2013 requires the use of room sensors and alarms to detect leaks of refrigerant belonging to all safety groups.

Question #3: The purpose of isopropyl alcohol is;

1. to regulate the pressure while evacuation

2. to remove air from the filter drier

3. to remove ice off the sight glass

4. to vent the refrigerant

Scroll down for the answer...

to remove ice off the sight glass

Ice forms on the sight glass at low temperatures that should be cleaned using an isopropyl alcohol spray.

Question #4: Pressure relief valves should never be installed in;

1. series.

2. parallel.

3. vertically.

4. horizontally.

Scroll down for the answer...

series.

Multiple pressure relief valve should never be installed in series to the system lines.

It may result in excessive loss of the fluid due to multiple valves releasing pressure at the same time.