I have a potential customer, in Scotland, with mixed commercial and residential premises. The property was formerly a pub with a property of multiple occupancy upstairs. The property currently has a 3-phase TN-C-S supply coming in to the DNO's fused distribution box in the attic, second floor, which supplies 3 single phase meters. The attic does not have full standing height and other than housing the DNO's supply it will become a storage area!
The DNO's 100 A fuses are labelled on the face of the distribution box below them with a Red, Yellow and Blue spot. Live feeds are supplied from the top of the box: the 'Red' phase feeds a Wylex 7-way metal CU via a modern digital meter with onward connection to 2 metal CUs in the First Floor accommodation; the 'Yellow' phase is connected via the same type of digital meter to a Hager 4-way metal enclosure with a single double pole switch which is believed to be redundant. Neutral feeds are provided to these meters via a single neutral cable from the bottom of the distribution box to a 3-way Henley block providing a separate distributor's tail to each meter. Earth connections are provided to the active and redundant CUs in the same way. The 'Blue' phase distributor's live and neutral tails are supplied from the top of the box and are fed in parallel to the dual rate, 'Economy 7', meter and what appears to be a time clock below. The consumer's tails from this meter are further split at 2 Henley blocks to provide 2 live and 2 neutral tails. Up to this point, the installation is clean, neat and tidy. The exact nature and quality of the rest of the installation is, at this moment, an unknown quantity. It is believed that the CUs in the first floor accommodation are within 2 m of the supply point.
The customer requires a domestic installation in the residential part of the premises, a substantial 3-4 bedroomed flat with 3 large double bedrooms and a very large living room. The commercial premises requires a single phase supply for normal services and a 3-phase supply to a kitchen facility for the Cafe Bar.
Statement 1 - The current DNO's arrangement is unsuitable for the customer's requirement and they should contact the DNO to reconfigure the supply. Discuss.
What configuration should I expect? Will an additional single phase supply be required? I am thinking that there will need to be at least a single phase meter for the residential premises and a 3-phase meter for the commercial premises. Will the DNO require a separate single phase meter for the commercial premises? Will the single phase for the commercial premises be drawn from one of the 3 phases supplying the kitchen? Who will be responsible for delivering the connection to the customer's tails for the single phase supply to the commercial premises?
Statement 2 - The customer's desire for a 3-phase supply in order to capitalise upon the lower cost of second hand 3-phase electrical kitchen equipment is a false economy as the total through-life costs of design, installation, testing, maintenance and disposal of both the installation and the equipment are likely to be more expensive! Discuss.
The customer has plans drawn up by an architect, now sacked, who appears to have failed to correctly record the customer's requirements. It has taken 3 hours of consultation to discover and roughly record the customer's 'current' requirements; no other competitor has consulted in this manner with the customer and appear to have taken the drawings at face value. The customer wants: maximum reuse of existing fixtures, fittings and infrastructure; a list of parts to purchase and a labour only quotation.
Statement 3 - I should walk away as further effort is unlikely to bring just rewards! Discuss.
The customer clearly has a requirement ... even if some aspects of it are unachievable or misguided etc. In order for a win-win situation to prevail, would you insist that in order to provide a realistic parts list and estimate for labour that the customer pay for an up-front comprehensive electrical inspection and test which would enable the real scope of the work to be identified, agreed and costed? If I invest further effort in providing what the customer has asked for, how should I look to cover the investment of my time on the design and costing activity?
The DNO's 100 A fuses are labelled on the face of the distribution box below them with a Red, Yellow and Blue spot. Live feeds are supplied from the top of the box: the 'Red' phase feeds a Wylex 7-way metal CU via a modern digital meter with onward connection to 2 metal CUs in the First Floor accommodation; the 'Yellow' phase is connected via the same type of digital meter to a Hager 4-way metal enclosure with a single double pole switch which is believed to be redundant. Neutral feeds are provided to these meters via a single neutral cable from the bottom of the distribution box to a 3-way Henley block providing a separate distributor's tail to each meter. Earth connections are provided to the active and redundant CUs in the same way. The 'Blue' phase distributor's live and neutral tails are supplied from the top of the box and are fed in parallel to the dual rate, 'Economy 7', meter and what appears to be a time clock below. The consumer's tails from this meter are further split at 2 Henley blocks to provide 2 live and 2 neutral tails. Up to this point, the installation is clean, neat and tidy. The exact nature and quality of the rest of the installation is, at this moment, an unknown quantity. It is believed that the CUs in the first floor accommodation are within 2 m of the supply point.
The customer requires a domestic installation in the residential part of the premises, a substantial 3-4 bedroomed flat with 3 large double bedrooms and a very large living room. The commercial premises requires a single phase supply for normal services and a 3-phase supply to a kitchen facility for the Cafe Bar.
Statement 1 - The current DNO's arrangement is unsuitable for the customer's requirement and they should contact the DNO to reconfigure the supply. Discuss.
What configuration should I expect? Will an additional single phase supply be required? I am thinking that there will need to be at least a single phase meter for the residential premises and a 3-phase meter for the commercial premises. Will the DNO require a separate single phase meter for the commercial premises? Will the single phase for the commercial premises be drawn from one of the 3 phases supplying the kitchen? Who will be responsible for delivering the connection to the customer's tails for the single phase supply to the commercial premises?
Statement 2 - The customer's desire for a 3-phase supply in order to capitalise upon the lower cost of second hand 3-phase electrical kitchen equipment is a false economy as the total through-life costs of design, installation, testing, maintenance and disposal of both the installation and the equipment are likely to be more expensive! Discuss.
The customer has plans drawn up by an architect, now sacked, who appears to have failed to correctly record the customer's requirements. It has taken 3 hours of consultation to discover and roughly record the customer's 'current' requirements; no other competitor has consulted in this manner with the customer and appear to have taken the drawings at face value. The customer wants: maximum reuse of existing fixtures, fittings and infrastructure; a list of parts to purchase and a labour only quotation.
Statement 3 - I should walk away as further effort is unlikely to bring just rewards! Discuss.
The customer clearly has a requirement ... even if some aspects of it are unachievable or misguided etc. In order for a win-win situation to prevail, would you insist that in order to provide a realistic parts list and estimate for labour that the customer pay for an up-front comprehensive electrical inspection and test which would enable the real scope of the work to be identified, agreed and costed? If I invest further effort in providing what the customer has asked for, how should I look to cover the investment of my time on the design and costing activity?
