Type III safety & ASHRAE 15: EPA 608 Practice Questions

What does ASHRAE 15 require in a machinery room housing a large chiller?

Machinery rooms need refrigerant detectors that alarm and start mechanical ventilation when the refrigerant reaches a set level.

Why is a refrigerant monitor especially important in an equipment room with an R-123 chiller?

R-123 is classified B1 (higher toxicity), so leaks must be detected early to protect people in the room.

Where should the discharge from a chiller's rupture disc be piped?

Relief devices are vented to the outdoors so a release does not fill the machinery room or enter building air intakes.

A large refrigerant release fills a chiller room. What equipment may be needed to enter safely?

A large release can displace oxygen and expose people to toxic levels. Ventilate and enter only with SCBA by trained personnel.

Why is refrigerant vapor from a chiller leak a suffocation hazard in a basement machinery room?

Refrigerant vapor sinks and collects in low spaces, pushing out oxygen. Detectors and ventilation protect workers.

Which gas must never be used to pressurize a chiller for leak testing?

Oxygen mixed with oil under pressure can explode. Use heat or dry nitrogen with a regulator.

When warming a chiller with hot water to raise pressure for a leak test, what must the technician avoid?

Too much heat raises pressure toward the rupture disc setting and can release the charge. Control the water temperature and watch the gauge.

In an R-1233zd(E) chiller room, a detector alarms but the refrigerant is A1. Why is the alarm still important?

Even lower-toxicity, nonflammable refrigerants can cause asphyxiation in large amounts, and the alarm also means refrigerant is being lost.

What protective equipment should be worn when handling liquid R-123 or connecting hoses to a chiller?

Liquid refrigerant can injure eyes and skin even at low pressure. Wear safety glasses and gloves.

Why should an open flame never be used near an R-123 leak?

Heat decomposes R-123 into acids such as hydrochloric and hydrofluoric acid, and possibly phosgene. Remove refrigerant and ventilate before any hot work.

Under ASHRAE 15, a machinery room refrigerant detector for a refrigerant such as R-123 must alarm at what level?

ASHRAE 15 sets the detector alarm at a value not greater than the refrigerant's occupational exposure limit (OEL, listed in ASHRAE 34), so people are warned before harmful exposure.

Before working on a chiller's electrical controls or motor starter, what should the technician do?

Chiller starters carry high voltage. Lockout/tagout prevents the equipment from being energized while someone is working on it.