5.1.6 Insulating Safety Helmet
Insulating safety helmet is a protective device used to protect the head of an electrician from electric shock,bruises or falling objects during live working.
1.Basic Structure and Function of Insulating Safety Helmet for Live Working
(1)Basic structure
Insulating safety helmet is composed of shell,lining,chin strap,rear band,etc.,without air hole.The inner and outer structures of the insulating safety helmet are shown as Figs.5-14 and 5-15.
Fig.5-14 Inner Structure of Insulating Safety Helmet
1-lining;2-connecting hole;3-lining joint;4-girdle/rear band;6-rear band regulator;7-chin strap;8-sweatband;9-backing;10-headband;11-locking;and 12-protective band
Fig.5-15 Outer Structure of Insulating Safety Helmet
1-shell;2-brim;3-visor;4-top support;and 5-plug
(2)Basic function
The helmet is worn on the head to protect the operator's head during live working,can shield the arc,cushions shock absorption and disperses stress,and protect against electric shock or mechanical damage.
2.Classification and Technical Specifications of Insulating Safety Helmet for Live Working
(1)Classification
The insulating safety helmet for live working mainly includes American,European,Japanese and domestic,and the colors are mainly white and yellow.
(2)Technical Parameters
The insulating safety helmet for live working is made of high-density composite polyester material.In addition to the mechanical strength that meets the safety testing standards of the helmet,it shall also meet the electrical testing standards for the relevant distribution and live working.The strength of the dielectric must meet the test requirements of 20kV/3min.
3.Inspection Items of Insulating Safety Helmet(https://www.daowen.com)
(1)For new insulting safety helmet,it is necessary to check whether there is a certificate of production and product certification issued by the labor department;then check if it is damaged,whether the thickness is uniform,whether the buffer layer and the adjustment belt and the elastic belt are complete and effective;and finally check the trademark,model,manufacturer name,production date and production license number on the helmet.
(2)The appearance inspection must be carried out on the insulated safety helmet before its use.The components of the safety helmet,such as the shell,the headband,the top lining,the chin strap,the rear buckle(or the headband buckle),etc.shall be intact.The cushion space between the shell and the top lining shall be between 25mm and 50mm.The test certificate is in good condition and within the validity period of the test.
(3)Periodical inspection shall be done for checking,depressions,cracks and wear and tear,it shall be replaced immediately if any abnormal phenomena are found,and it shall not be used any more;any insulated safety helmet subject to thump,electric shock or crack shall be scrapped,regardless of whether it is damaged or not;its insulation performance shall be tested.
The insulated safety helmet shell shall not have breathable holes and shall not be confused with ordinary ones.
4.Usage for Insulated Safety Helmet
(1)When the operator wears the insulated safety helmet,the rear adjusting belt of the helmet is adjusted to a suitable position according to the head shape(the head is slightly restrained,but not uncomfortable to the extent that the safety helmet will not fall off when the chin strap is not fastened).The chin band must be fastened when the operator wears the insulated safety helmet.the chin strap shall be close to the jaw so that the jaw is restrained but not uncomfortable.Then elastic strap in the helmet is fastened.The tightness of the buffering cushion is regulated by the strap,and the vertical distance between the top of the head and the top of the helmet body is generally between 25mm and 50mm,and at least not less than 32mm.
(2)After the safety helmet is worn,the rear buckle shall be screwed to an appropriate place(or the headband buckle is adjusted to an appropriate place),and the chin strap is locked to prevent slipping due to tilting forward and backward or other reasons during work.It is prohibited to put the insulated safety helmet askew,or put your hat on the back of the brain.Otherwise,it will reduce the protective effect of the safety helmet.
(3)The lower jaw strap of the insulated safety helmet must be buckled and fastened under the jaw,with moderate tightness.This prevents the safety helmet from being blown off by strong winds,knocked off by other obstacles,or falling off due to back-and-forth swings of the head.
(4)It is strictly prohibited to use the insulated safety helmet with only the chin strap connected to the shell,that is,the insulated safety helmet without a cushion layer therein.
(5)It is strictly prohibited to use the safety helmet in a non-standard manner.During the field operation,the operators shall not take off the safety helmets and put them aside or use them as cushions,shall not unfasten the buckle or not tighten it,and shall not put the buckle strap into the lining.
(6)When the insulated safety helmet is used usually,it shall be kept clean,can not contact the source of fire,and shall not applied with paint at will.
5.Precautions for Storage of Insulated Safety Helmet
(1)The insulated safety helmet shall not be stored in acid,alkali,high-temperature,sunlight and humid places,and even shall not be placed with hard objects together.
(2)The insulated safety helmet shall be kept in the warehouse of special live working tools with constant temperature and humidity,and shall be placed separately to avoid mixing with ordinary safety helmets.
(3)The suitable temperature of the safety helmet is-10～+50°C.It shall be placed in a dry place with breathable air,and avoid contact with fire(heat)source and erosive substances,so as not to affect its normal service life.The storage period of the safety helmet shall be shortened as far as possible,and it is better to use it immediately after being purchased.The products with short time of delivery shall be purchased,so as not to affect the actual effective use time due to the excessive storage time.
6.Test Contents of the Insulated Safety Helmet
(1)The delivery test of insulated safety helmet includes impact absorption property test(the impulse test shall be done after low temperature,high temperature and water spraying pretreatment,and the force transmitted to the head model shall not exceed 4,900N),puncture resistance property test,electrical insulation property test,flame retardant property test,lateral rigidity test and antistatic property test.
(2)The insulation safety helmet shall be tested periodically,and the mechanical test and electrical test shall be conducted once a year.Only after passing the test can be used continuously.