Household and similar electrical appliances - Safety - Particular requirements for instantaneous water heaters
1 Scope
This clause of GB 4706.1-2005 is applicable except as follows.
This Standard deals with the safety of electric instantaneous water heaters for household and similar purposes and intended for heating water below boiling temperature, their rated voltage being not more than 250 V for single-phase appliances and 480 V for other appliances.
Note 101: Instantaneous water heaters incorporating bare heating elements are within the scope of this standard.
Appliances not intended for normal household use, but that nevertheless may be a source of danger to the public, such as appliances intended to be used by laymen in shops, in light industry and on farms, are within the scope of this part.
As far as is practicable, this part deals with the Common hazards presented by appliances that are encountered by all persons in and around the home. However, in general, it does not take into account:
——The use of appliances by young children or infirm persons without supervision;
——Playing with the appliance by young children.
Note 102: Attention is drawn to the fact that
——For appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be necessary;
——In many countries additional requirements are specified by the national health authorities, the national authorities responsible for the protection of labour and similar authorities.
——In many countries regulations exist for the installation of equipment connected to the water mains.
Note 103: This part does not apply to:
——Appliances for boiling water (GB 4706.19);
——Storage water heaters (GB 4706.12);
——Appliances intended exclusively for industrial purposes;
——Appliances intended to be used in locations where special conditions prevail, such as the presence of a corrosive or explosive atmosphere (dust, vapour or gas);
——Commercial dispensing appliances and vending machines (GB 4706.72).
2 Normative references
This clause of GB 4706.1-2005 is applicable.
3 Definitions
This clause of GB 4706.1-2005 is applicable except as follows.
3.1.9 Replacement:
normal operation
operation of the appliance while supplied with water, the flow being adjusted to attain the highest outlet water temperature without operation of the thermal cut-out
3.101
instantaneous water heater
stationary appliance for heating water while it flows through the appliance
3.102
closed water heater
instantaneous water heater intended to operate at the pressure of the water system, the flow of water being controlled by one or more valves in the outlet system
Note: The operating pressure may be the output pressure of a reducing or boosting device.
3.103
open-outlet water heater
instantaneous water heater in which the flow of water is controlled by a valve in the inlet pipe, there being no valve in the outlet pipe
3.104
bare-element water heater
instantaneous water heater in which uninsulated heating elements are immersed in the water
3.105
rated pressure
water pressure assigned to the appliance by the manufacturer
3.106
flow switch
device that operates in response to a flow of water
3.107
pressure switch
device that operates in response to a change in pressure
Foreword I
IEC foreword III
Introduction VII
1 Scope
2 Normative references
3 Definitions
4 General requirements
5 General conditions for the tests
6 Classification
7 Marking and instructions
8 Protection against access to live parts
9 Starting of motor-operated appliances
10 Power input and current
11 Heating
12 Void
13 Leakage current and electric strength at operating temperature
14 Transient overvoltages
15 Moisture resistance
16 Leakage current and electric strength
17 Overload protection of transformers and associated circuits
18 Endurance
19 Abnormal operation
20 Stability and mechanical hazards
21 Mechanical strength
22 Structure
23 Internal wiring
24 Components
25 Supply connection and external flexible cords
26 Terminals for external conductors
27 Provision for earthing
28 Screws and connections
29 Clearances, creepage distances and solid insulation
30 Resistance to heat and fire
31 Resistance to rusting
32 Radiation, toxicity and similar hazards
Annexes
Bibliography
Figure 101 Diagram for the leakage current measurement for single-phase bare-element water heaters
Figure 102 Diagram for the leakage current measurement for three-phase bare-element water heaters
Figure 103 Diagram for the leakage current measurement for single-phase bare-element water heaters supplied by a supply cord fitted with a plug
