Safe Use Of Electricty Under Water Flashcards
What time frame must a protected circuit be?
20 milliseconds
30mA
Irrespective of voltage,( 50v +) how many ohms is a typical worst case figure for limb to limb contact on a diver?
500 ohms
If the voltage was 50v or less, what’s is the max amount of ohms considered safe for a diver?
750 ohms
What voltage is considered to be classed as high voltage?
A) 750 V
B) 1000V
C) 1500V
D) 2000V
B) 1000V
What voltage is considered to be classed as a low voltage?
A) any voltage up to 50V
B) any voltage up to 100v
C) any voltage up to 150v
A) any voltage up to 50V
What are the voltage ranges, to be considered for medium voltage?
50v-1000v
How many volts would be considered to be classed as ultra high?
30,000v
In diving, what is considered to be a safe range of frequency for a diver?
A) 40-50 Hz
B) 50-60 Hz
C) 50-70 Hz
D) 40-100 Hz
B) 50-60Hz
What is the maximum voltage for a diver on a dc circuit without a trip device?
30v
What is the normal voltage for a diver on a dc circuit without a trip device?
24 volts
What is the maximum voltage for a diver on an ac circuit without a trip device?
7.5 volts
What is the normal voltage for a diver on an ac circuit without a trip device?
6 volts
What is the maximum voltage for a diver on a dc circuit with a trip device?
285v
What is the normal voltage for a diver on a dc circuit with a trip device?
250 Volts
What is the maximum voltage for a diver on an ac circuit with a trip device?
250 volts
What is the normal voltage for a diver on an ac circuit with a trip device?
220 volts
A diver is using a welding/cutting tool under water. Is this tool the positive or negative side of the circuit?
Negative
Positive to be clamped to the cut/welded part of the metal.
A welding cable should comprise of what?
Two fully-insulated conductors
What is the typical instrument voltage inside hyperbaric chamber?
220 volts ac protected by an RCD
What voltage is currently used inside a diving bell?
24 volt dc no active protection
What are the external bell lights circuit set up?
220 v ac on an RCD protection
What voltage circuit is used for internal lights on a welding habitat?
24v dc
Preheat for a habitat runs on what voltage?
100Volts
What percentage of ripple affect will dc be treated as ac?
5%