Skills Learning – Inspection of High Pressure Termination, Manual Suction and Use of Fire Extinguisher

1、 High voltage suspension and inspection

Take the disassembly of DC / DC converter of BAIC EV series pure electric vehicles as an example.

  1. Precautions

① During vehicle maintenance, non relevant personnel are not allowed to touch the vehicle at will.

② Do not touch the parts with high voltage warning signs at will.

③ If relevant high-voltage components need to be disassembled, the disassembly personnel must participate in the high-voltage safety training and be familiar with the high-voltage system

④ Operators also need to attend first aid training for high voltage accidents (if organized by the Red Cross)

⑤ When operating high-voltage components, operators need to wear labor protection articles and insulating gloves.

inspection of insulating gloves
inspection of insulating gloves

⑥ When operating exposed high-voltage system components, a multimeter must be used to measure whether there is high-voltage power to ensure that there is no high-voltage power before operation. The multimeter shall be calibrated regularly, and the internal resistance shall not be less than 10m Ω.

⑦ Turn off the vehicle after driving. If it is necessary to disassemble the high-voltage system, wait for 5min.

⑧ When removing or assembling electrical components, the 12V power supply and the manual maintenance switch on the high-voltage battery must be disconnected.

⑨ After the disassembly and assembly of high-voltage components and before connecting the high-voltage power again, it is necessary to check the assembly and connection of all high-voltage components to ensure their reliability.

⑩ All high voltage components should be well grounded.

  1. Protective measures

① Anti high voltage gloves: insulated rubber gloves suitable for electrical operation.

② Safety goggles: prevent electrolyte overflow.

③ High voltage insulated shoes: they are mainly used as auxiliary safety tools in electrical operation of high-voltage power equipment. It can be used as a basic safety appliance below 1KV.

④ Fire extinguisher: carbon dioxide type fire extinguisher is used for high-voltage power battery, and a large amount of continuous water can also be used for fire extinguishing.

⑤ Absorbent towel or cloth: after neutralizing the spilled electrolyte, use a absorbent towel to absorb the excess electrolyte.

⑥ Insulating tape: cover all high-voltage wires or terminals with insulating tape. If the maintenance plug is pulled out, wrap the maintenance plug slot with insulating tape.

⑦ Maintenance workbench: the maintenance workbench with insulating rubber on the working face must be used.

  1. Operation process

① Place the vehicle key in off gear and wait for the high-voltage capacitor to discharge for 5min.

② Remove the key, open the engine hood and support it, and lay the fender cloth.

③ Disconnect the negative cable of low-voltage battery.

④ For models with power distribution unit (PDU), such as 2016 ev160, ev200 and other models, disconnect the low-voltage connector at the left rear of PDU.

⑤ Check the insulating gloves as shown in the figure.

a. Confirm that there is no crack, wear and other damage.

b. Roll up the edges of the gloves.

c. Fold the opening and seal the glove opening.

d. Blow air into the gloves to confirm that there is no air leakage.

e. Check the second glove in the same way.

f. Wear gloves after confirming good sealing.

⑥ Disconnect the high-voltage harness socket of the power battery and cut off the high-voltage power. Note: BAIC new energy vehicles are usually not equipped with special maintenance switches. Note: high voltage power failure must be operated by electrical qualified personnel and high voltage safety warning signs must be placed.

⑦ Use a special multimeter to measure the voltage of DC / DC components. If the measured value is greater than 0V, use a special discharge rod to discharge the part until the multimeter confirms that the voltage disappears completely.

2、 Artificial sipping

Move the injured patient to a place with fresh air as soon as possible and keep a breathing posture for rest. If the injured patient is not breathing, implement artificial respiration and call for help. The operation process of correctly implementing artificial respiration rescue is as follows.


determine whether the injured patient has a conscious response
determine whether the injured patient has a conscious response

② If the injured patient has no conscious response, he should shout for help.

③ If the injured patient has a conscious response, move the injured patient first to make him lie flat.

ask for help and turn the patient over
ask for help and turn the patient over

④ Untie the collar of the injured patient and remove the foreign bodies in the mouth and nose. It is best to put a cushion under his neck to tilt his head back and open his mouth,.

⑤ Check whether the injured patient is still breathing. Note that the time should not exceed 10s.

unblock breathing and check respiratory tract
unblock breathing and check respiratory tract

⑥ The rescuer inhales deeply, aligns and clings to the mouth of the injured patient, pinches the nostrils of the injured patient with one hand, and blows hard.

⑦ After the blowing stops, loosen the hand pinching the nose, raise the head, inhale deeply again, and repeat the above blowing action. The number of blows per minute is similar to the usual breathing rate. After 5 ~ 10 blows, stop and check whether the injured patient has a pulse (or signs faster than the original pulse).

⑧ Continue artificial respiration until the injured patient can breathe autonomously. Be patient and insist on not giving up.

3、 Use of dry powder fire extinguisher (MF)

 Use of dry powder fire extinguisher (MF)
Use of dry powder fire extinguisher (MF)

① Before use, turn the bottle upside down several times to loosen the dry powder in the bottle, and then remove the lead seal (or plastic seal).

② Remove the safety pin.

③ The left hand holds the nozzle and the right hand holds the pressure handle.

④ At a place 2m away from the flame, press down the handle with your right hand, swing the nozzle left and right with your left hand, and spray dry powder to cover the combustion area until all the fires are extinguished. Note: the operator should stand upwind of the wind direction.

Read more: How to do high voltage safety protection?