Garden Hot Tub Protection

[lews123]

Hi Guys, anyone with experience in installing hot tubs? Had a call from a client asking to install hot tub and before I head round the house I'm just thinking about best means of protection. Any thoughts are appreciated

 

[telectrix]

manufacturers instructions should guide you here.

 

[lews123]

manufacturers instructions should guide you here.

O really ok, I'll take a look. Thanks

 

[Andy78]

Depends what sort of protection. If it's from peeping toms then a high fence should suffice.

 

[DuaneMHunt1976]

And a few people tend to go Nude in Hot Tubs so Condoms that work in Hot Waters is good idea.:clown:

Or a shower cap if you dont want to get your hair wet:sultan:

 

[Buckfast]

Hi Guys, anyone with experience in installing hot tubs? Had a call from a client asking to install hot tub and before I head round the house I'm just thinking about best means of protection. Any thoughts are appreciated

As telectrix advises manufactures instructions must be complied with. 30mA Rcd protection required and also check earthing system. Personally i never install to a PME supply and would always use a TT system. IET Guidance Note 7 has a small section on hot tubs stating that BS7671 Section 702 should be applied in full.

 

[lews123]

As telectrix advises manufactures instructions must be complied with. 30mA Rcd protection required and also check earthing system. Personally i never install to a PME supply and would always use a TT system. IET Guidance Note 7 has a small section on hot tubs stating that BS7671 Section 702 should be applied in full.

thanks very much, thats helpful

 

[Richard Burns]

I received this information about hot tubs from Amberleaf
Note that it is 2008 so not accounting for AMD 3
(Sorry no pretty pictures)
Locations : Date Issued: July 2008

Containing a hot tub or garden spa

Contents

1. Introduction
2. Increased risk of electric shock
3. Indoor hot tubs
4. Garden spas
5. Hybrid spas
6. Protective multiple earthing (PME)

1) Introduction
The increasing use of hot tubs and garden spas, in both indoor and outdoor locations, has brought with it an increase in the number of questions posed about the safety requirements for the associated electrical installations. The questions raised result from the need to know what particular requirements of BS 7671 should be applied to a given situation. For example, should the requirements set out in Section 701, Section 702, or both, be applied in addition to the general requirements
The product specification relevant to hot tubs and garden spas is BS EN 60335-2-60: Specification for safety of household and similar appliances: Particular requirements for whirlpool baths and whirlpool spas.

2) Increased risk of electric shock
As with rooms containing a bath tub or shower basin, the indoor hot tub introduces an increased risk of electric shock due to the reduction in body resistance, particularly contact resistance, due to immersion, or partial immersion, in water. For hot tubs located outdoors and garden spas, the risk of electric shock is further increased because contact with the general mass of Earth is likely. (Touch voltages under earth fault conditions are increased due to persons being in contact with ‘true’ Earth, i.e. the ground.)
3) Indoor hot tubs
Where a hot tub is placed in a location containing a bath or shower, the requirements of Section 701 have to be met. However, where a hot tub is located indoors, it may be placed in a room other than the bathroom. Where a hot tub is located in a room other than a bathroom, whether on the ground floor or elsewhere indoors, the location will be subject to similar electrical safety considerations as a bathroom. In such cases, the electrical installation designer may decide that the requirements of Section 701 should be applied in full.

4) Garden spas
Where the garden spa is housed in a purpose-made spa-shelter (Fig 1 ), the location will be subject to similar electrical safety considerations as a bathroom, and the most appropriate requirements to apply are likely to be those of Section 701.

Garden spa in purpose-made shelter

Fig 1
Where the garden spa is an ‘open-air’ type (Fig 2 ), the location falls within the scope of Regulation 702.11 (basins of swimming pools, fountains and paddling pools, and their surrounds). The requirements of Section 702 should therefore be applied in full for this type of installation.

Open-air garden spa

Fig 2

Larger type ‘swim spas’, as shown in Fig 3, again would be subject to the requirements of Section 702.
Swim spa
Fig 3

Hybrid spas
Where a spa does not fit into either of the categories referred to in items 3 or 4, the electrical installation designer must use engineering judgment in applying the relevant requirements. Electrical equipment should be suitable for the particular external influences likely to occur at its point of installation, and any additional measures considered necessary for protection against electric shock should be deployed. For example, as cited in the note to Section 415, additional protection in accordance with Section 415 may be specified with the protective measure under certain conditions of external influence and in certain special locations. This may include:
• protection by an RCD with a residual operating current not exceeding 30 mA, and/or
• supplementary bonding.

Another measure of protection against electric shock which may be used is separated extra-low voltage (SELV) meeting the requirements given in Sections 701 and/or 702 of BS 7671.
The relevant requirements of BS 7671 need to be complied with, so that the degree of electrical safety is not less than that afforded in a location containing a bath or shower, or a location containing a swimming pool.

Protective multiple earthing (PME)
Where earthing is by PME, it should be noted that electricity distributor’s notes of guidance often contain particular requirements relating to electrical installations in locations containing swimming or paddling pools or the like, or do not permit PME earthing to be extended outside buildings in which there is an insulated floor and main protective bonding is provided.
The use of PME by the distributor is conditional on certain requirements being met both in the distributor’s network and in the consumer’s installation (see item 3 of this topic).
BS-7671: ( Requirements for electrical installations )
Additional protection Section 415
Locations containing a bath or shower Section 701
Swimming pools and other basins Section 702

Earthing : Date Issued: July 2008

Protective Multiple Earthing (PME)

Contents
1. Introduction
2. Definition and description
2.1 The supply neutral conductor
2.2 The PME earthing terminal
3. Considerations relating to the use of a PME earthing terminal
3.1 Availability and use
3. 3.1.1 Perceived electric shock
3. 3.1.2 Danger arising from loss of the PEN conductor
3. 3.1.3. Hazardous area
3. 3.2 Responsibilities and requirements where a PME earthing terminal is used
4 . Distributors other than Public Electricity Distributors

1) Introduction

Protective Multiple Earthing (PME) is an earthing arrangement commonly used by electricity distributors for their distribution networks, where the supply neutral conductor provides the functions of both protective and neutral conductors. Where PME is used, the supply neutral conductor is often referred to as a PEN (combined protective and neutral) or CNE (combined neutral and earth) conductor. To improve the security of the earthing arrangement, the supply PEN conductor is earthed at several points.

Most new low voltage supplies to electrical installations are provided with a PME earthing terminal.

2) Definition and description

Protective Multiple Earthing (PME) is defined in Part 2 of BS 7671 as:

‘An earthing arrangement, found in TN-C-S systems, in which the supply neutral conductor is used to connect the earthing conductor of an installation with Earth, in accordance with the Electricity Safety, Quality and Continuity Regulations 2002 as amended.’

The Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR) permits distributors to provide an earthing terminal connected to the supply neutral conductor (the supply PEN conductor) as an earthing facility for the consumer’s installation. See item 4 of this topic.

The use of PME by the distributor is conditional on certain requirements being met both in the distributor’s network and in the consumer’s installation (see item 3 of this topic).

A PME supply is best described by reference to the diagram in Fig1, which shows an electrical installation connected to a three-phase supply. The supply PEN conductor has been connected to Earth by the electricity distributor at several points in accordance with requirements given in the ESQCR, thereby providing a low resistance connection between all parts of that conductor and Earth. The distributor has provided an earth connection (the PME earthing terminal) and the consumer is using this as the means of earthing for the electrical installation.

 

[stevethesparks]

You may find this link useful:
http://library.ukpowernetworks.co.u...017+Customer+Installation+Earthing+Design.pdf

 

[Buckfast]

You may find this link useful:
http://library.ukpowernetworks.co.u...017+Customer+Installation+Earthing+Design.pdf

Thanks for this document. I am very interested in others views on this topic, PME or TT for hot tubs. As i have stated earlier, on a pme installation i alway connect hot tub (Always been in garden) to a TT installation.
Section 702.410.3.4.3 states that a suitable earth mat/electrode with a resistance of 20 ohms or less connected to the protective equipotential bond would suffice along with rcd protection. In a normal domestic installation how achievable is this ?. In my kneck of the woods we have very little soil and mainly limestone and although at times i can get down to this resistance i would not like to guarantee its longevity during changeable climatic conditions, and therefore go for TT every time which gives me that extra margin of drift.

 

[Midwest]

Here's one we made earlier! http://www.electriciansforums.co.uk...ral-electrical-forum/105210-hot-tub-help.html
Shame there's not a sticky on hot tubs, as it gets asked so regularly.