Stay Hydrated and Cool

When it gets really hot, evaporation of sweat is all that stands between you and heat exhaustion. That is really your ace in the hole. The body perspires and the sweat evaporates to cool you off. When you are working in a hot environment you sweat a great deal – and that is good. However, it is important to replace the water. That is why you should have lots of water available and drink water continually while working.

Weather conditions can play a big part as well. A relative humidity over 60% (pretty much all summer in Georgia) slows the evaporation process, increasing the likelihood of heat exhaustion. When the heat index exceeds 90, you need to be careful. When it exceeds 100, you need to be extra careful. Besides hydration, stay out of direct sun and seek cool shelter whenever possible. Time spent in attics should be limited and preferably only in the early morning or evening.
  
Failure to drink enough water can lead to dehydration. Failure to stay hydrated and cool can lead to heat exhaustion, which can be dangerous. If you continue to ignore your body’s warning signals, heat stroke can occur, which is a medical emergency. You are no help to anybody passed out somewhere. If you are thirsty and really tired – TAKE A BREAK AND DRINK SOME WATER! Finally, note that we are drinking water; NOT beer or caffeinated soft drinks. Symptoms of dehydration, heat exhaustion, and heat stroke are listed below.

Symptoms of dehydration include:
• fatigue
• loss of appetite
• flushed skin
• heat intolerance
• light-headedness
• dark-colored urine
• dry cough  

Symptoms of heat exhaustion include:
• Confusion
• Dark-colored urine (a sign of dehydration)
• Dizziness
• Fainting
• Fatigue
• Headache
• Muscle or abdominal cramps
• Nausea, vomiting, or diarrhea
• Pale skin
• Profuse sweating
• Rapid heartbeat

Symptoms of heat stroke include:
• Throbbing headache
• Dizziness and light-headedness
• LACK OF SWEATING DESPITE THE HEAT
• Red, hot, and dry skin
• Muscle weakness or cramps
• Nausea and vomiting
• Rapid heartbeat, which may be either strong or weak
• Rapid, shallow breathing
• Confusion, disorientation, or staggering
• SEIZURES
• UNCONSCIOUSNESS

Grounded Compressor Behavior

Typically, a grounded compressor does not really do anything – that is the compressor does nothing. The breaker, or fuse does plenty. Normally the breaker trips and/or the fuse blows as soon as the compressor is energized. In the case of many units with single pole contactors, the breaker may trip and/or the fuse blow as soon as power is turned on to the unit – even if the contactor is not closed. This is because power from one leg feeds the compressor and condenser fan motor all the time. If that leg of power is grounded, the breaker will normally trip immediately.

Occasionally a grounded compressor can cause the condenser fan motor to run slowly all the time. The fan gets one leg of power all the time. If the leg of the compressor that is fed by the normally open pole of the contactor is grounded, that provides a path for the current, causing the fan motor to receive close to 120 volts. With these units, the breaker does not trip until the contactor closes. I have even seen compressors which had a high resistance ground operate, even though they were grounded. If the ground is hundreds, or thousands of ohms, the current passing through to ground will not be enough to blow fuses or trip breakers. This type of ground is most often caused by system contamination creating a path inside the compressor shell.

The other day I experienced a type of grounded compressor which I had not seen before. When I arrived, the compressor would try to start for several minutes, and then the breaker would trip. The fan would run and the compressor would hum. Immediately I thought “capacitor.” But the capacitor checked out. So did the wiring. I then decided to check the amp draw to the compressor. On L1 the amp draw was 0, yet I could hear the compressor humming. I looked at my meter to make sure I had it set correctly and that it was not on hold. Then I decided to check the amps on L2, and read 65 amps. This is a single phase motor. Where are the amps going? Finally, I checked the amp draw on the bonding ground wire and read 24 amps. Current was travelling from L2 to ground – indicating a grounded compressor. The fact that not all of the current was travelling through the bonding ground concerned me, so I turned off the breaker. I then verified that the compressor was grounded by ohming it out. I was there for a second opinion, and I verified that the compressor was dead. I also advised the owner against trying to operate the unit any more, explaining that current traveling through ground is dangerous.