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Velis Evo - UK Manual

  • Text
  • Heater
  • Water
  • Evo
  • Manual
  • Velis
  • Installation
  • Heater
  • Electrical
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Suggest ways of

Suggest ways of terminating discharge pipes safely Temperature & pressure relief valve Metal discharge pipe (D1) from temperature & pressure relief valve. to tundish. Tundish 600 mm Max. 300 mm Min. Metal discharge pipe (D2) from tundish with continuous fall. See Table 2 and worked example. Discharge below fixed grating. (see page 6 for alternative points of discharge). Fixed grating Trapped gulley iv) Where a single pipe serves a number of discharges, such as in blocks of fl ats, the number served should be limited to no more than 6 systems so that any installation can be traced reasonably easily. The single common discharge pipe should be at least one pipe size large than the largest individual discharge pipe to be connected. If unvented hot water storage systems are installed where discharges from safety devices may not be apparent i.e. in dwellings occupied by the blind, infi rm or disabled people, consideration should be given to the installation of an electronically operated device to warn when discharge takes place. Note: The discharge will consist of scalding water and steam. Asphalt, roofi ng felt and non-metallic rainwater goods may be damaged by such discharges. Table 2 Sizing of copper discharge pipe “D2” for common temperature valve outlets Valve outlet size Minimum size of discharge pipe D1* Minimum size of discharge pipe D2* from tundish Maximum resistance allowed, expressed as a length of pipe (i.e. no elbow or bends) Resistance created by each elbow or bend G 1/2 15 mm 22 mm 28 mm 35 mm G 3/4 22 mm 28 mm 35 mm 42 mm G 1 28 mm 35 mm 42 mm 54 mm Up to 9 m Up to 18 m Up to 27 m Up to 9 m Up to 18 m Up to 27 m Up to 9 m Up to 18 m Up to 27 m 0.8 m 1.0 m 1.4 m 1.0 m 1.4 m 1.7 m 1.4 m 1.7 m 2.3 m 10 / EN

WORKED EXAMPLE The example below is for a G 1/2” temperature & pressure relief valve with a discharge pipe (D2) having 4 no. elbows and length of 7 m from the tundish to the point of discharge. From Table 2 Maximum resistance allowed for a straight length of 22 mm copper discharge pipe (D2) from G 1/2” T & P valve is 9 m. Subtract the resistance for 4 no. 22 mm elbows at 0.8 m each = 3.2 m. Therefore the maximum permitted length equates to: 5.8 m. As 5.8 m is less than the actual length of 7 m therefore calculate the next largest size Maximum resistance allowed for a straight length of 28 mm pipe (D2) from G 1/2” T & P valve equates to: 18 m. Subtract the resistance for 4 no. 28 mm elbow at 1.0 m each = 4 m. Therefore the maximum permitted length equates to: 14 m As the actual length is 7 m, a 28 mm (D2) copper pipe will be satisfactory. DRAINING THE APPLIANCE The appliance must be drained if left inactive in a room subject to frost and/or in the event of prolonged inactivity. Typical drain arrangement and system designs will vary: 1. Turn power off to ensure appliance is not operated when empty. 2. Turn off cold supply to appliance. 3. Shut off hot water feed from appliance. 4. Connect hose to drain cock and place other end in sink, basin etc. 5. Open drain cock and open TPR valve to vent cylinder. ELECTRICAL WARNING The appliance must be earthed The electrical installation must be in line with the current I.E.E. wiring regulations. A mains supply of 240 VAC 3 kW (13 amps) is required (Fig. 2) Heat resisting cable, round 3 core 1.5 mm (to BS 6141 table 8) should be used to connect to the electrical supply through either: - a 13 amp socket to BS 1363; or - a double pole fused isolating switch with a contact separation of 3 mm minimum on each pole. Flexible cables are colour coded as follows: Brown ................................................................. live Blue ..................................................................... neutral Green and yellow ........................................... earth 11 / EN