Crown Boiler BIMINI BUDDY BWC090, Руководство по установке

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APPENDIX A
Optional Method for Retrofitting BWC Boilers into Existing Circulator Zone Systems
The piping/wiring method shown in this Appendix is sometimes useful in retrofit applications where the old boiler
was installed with circulator zones. The piping shown in this Appendix may offer the advantage of fewer changes to
existing piping. In addition, if one of the original zones was used for an indirect water heater, the piping in this Appendix
may allow the original indirect water heater circulator to be reused.
To use this piping/wiring method, observe the following guidelines:
1) In this manual, the “boiler loop” is defined as the piping running directly from the boiler supply to the boiler
return. The boiler loop pipe size, maximum equivalent length, and circulator size are determined using Table 9.5
as described in Section IX. Note that the pipe size shown in Table 9.5, column (a) is the minimum allowable
size; larger pipe and fittings can be placed in the boiler loop as long as there are no size transitions near the
“closely spaced tees” (see 2 below).
2) Connect the original zone manifolds into the two closely spaced tees shown in Figure A.1. These two tees must
be no more than 12” apart. At least 8 diameters of straight pipe must be installed upstream of the upper (supply)
tee and at least 4 diameters downstream of the lower (return) tee. If the original zone manifold piping
is larger than the boiler loop piping, best results will be achieved by making all boiler loop piping between
the closely spaced tees, and for at least 8 diameters upstream and 4 diameters downstream, equal to the
larger size. For example, if the boiler loop piping is 1” and the original zone manifolds are 1-1/4”, the boiler
loop piping between the tees should be 1-1/4”, along with at least 10” of straight pipe upstream and 5” of
straight pipe downstream of the two tees.
3) Use the wiring shown in Figure A.2 if either of the following are true:
• All zones are for heating
• One of the zones is for an indirect water heater, which uses the same supply water temperature as the
heating zone/s (this condition will not be met if the outdoor temperature sensor is connected to the
boiler).
4) Use the wiring shown in Figure A.3 where one of the zones is for an indirect water heater which requires a
different supply water temperature than that for the heating zone/s.
Figure A.1: Optional Retrofit Piping Method