Circuit breaks on temperature rise. 10) Expansion tanks, air scoops and other components left out for clarity. 11) Observe all applicable plumbing and electrical codes. This diagram is for reference only. The installer or designer is responsible for the proper selection and design of the system. A4. 3-way RTC in Primary/Secondary - Heating and DHW using Indirect Water Heater on Primary Loop; without Outdoor Reset (ELECTRICAL) A1 = Aquastat, Indirect DHW Tank C1 = Mixing Valve Actuating Motor P1 = Boiler Circulator P2 = Indirect Circulator R1 = Relay S1 = Boiler Return Sensor Z1...Z2 = Zone Valves, Zone Relays, thermostats or BMS signal CfcaBs II T NOTES: 1) Refer to the l&O to determine correct valve orientation and actuator wiring. 2) 120 VAC supplying the RTC should be separate from the burner/boiler circuit. 3) Heat demand can be any electrical signal consisting of 24 - 240 VAC. 4) Use isolation relays for circulators greater than 1/3 HR Use motor starters for 3 phase circulators. 5) System Pump (P3) to be operated by zone relay or other installer supplied device. This diagram is for reference only. The installer or designer is responsible for the proper selection and design of the system. A5. 3-way Multiple Boiler RTC in Primary/Secondary - Heating and DHW using Indirect Water Heater on Primary Loop; Using Sequencer with & without Outdoor Reset (MECHANICAL) 120V (ac) ■ Class 11 T ransformer | Outdoor Sensor {S4 ) 070 * 2dV (ai A1 ~ Aquastat Indirect Hot Water C1, C2 = Diverting Valve Actuating Motor M1,M2 = By-Pass Mix Point P1, P2 = Boiler Circulator P3 - System Pump (runs on call for heat) P4 = indirect Circulator R1 = Relay S1, S2 = Boiler Return Sensor 53 = Mix Supply Sensor 071 54 = Outdoor Sensor 070 V1, V2 = 3-Way Diverting Valve V3 = Ball Valve, Balancing Z1 ...Z3 = Zones tmS) NOTES: 1) Install the boiler as indicated above for systems where return temperatures may be less than 135F and heating/DHWwith an indirect water heater. 2) The Outdoor Sensor (S4) and the Mix Supply Sensor (S3) are required when the Outdoor Reset feature is selected. An appropriate sequencer must also be selected. The mix sensor must be installed 10 pipe diameters downstream of the system pump, in the primary loop. The mix sensor must be secured to the surface of the pipe using a wire tie or similar device. 3) The by-pass piping, diverting valve and boiler circulator must be sized using the sizing charts found in Appendix B. 4) A domestic hot water priority could be used provided the diversion from the heating system loop does not impact the system heater’s performance. 5) Closely spaced tees must connect the branch to the larger header. The Tee centerlines must be no greater than 4 times the larger header pipe diameter. 6) The diverting valves, V1 & V2, must be no greater than 11 linear feet of pipe from the Return Sensors, S1 & S2. 7) There shall be a MINIMUM of 4 linear feet of pipe between the By-pass Mix Points, M1 & M2, and the Return Sensors, S1 & S2. 8) The balancing valves in the boiler return lines, V3, may be necessary in low head by-pass loop applications. 9) The indirect heater aquastat (A1) is a normally closed switch. Circuit breaks on temperature rise. 10) Expansion tanks, air scoops and other components left out for clarity. 11) Observe all applicable plumbing and electrical codes. This diagram is for reference only. The installer or designer is responsible for the proper selection and design of the system. A5. 3-way Multiple Boiler RTC in Primary/Secondary - Heating and DHW using Indirect Water Heater on Primary Loop; Using Sequencer with & without Outdoor Reset (ELECTRICAL) A1 =■ Aquastat, Indirect Hot Water M1 = By-Pass Mix Point C1. C2 - Diverting Valve Actuating Motor PI. P2 - Boiler Circulator P3 - System Pump (runs on call for heat) P4 = Indirect Circulator R1 = Relay S1, S2 - Boiler Return Sensor 071 53 = Mix Supply Sensor 071 54 = Outdoor Sensor 070 21 .Z3 = 2one Valve, Zone Relays, thermostats or BMS signal C2 CW - Open to System NOTES: 1) Refer to the l&O to determine correct valve orientation and actuator wiring. 2) 120 VAC supplying the RTC should be separate from the burner/boiler circuit. 3) Heat demand can be any electrical signal consisting of 24 - 240 VAC. 4) Use isolation relays for circulators greater than 1/3 HR Use motor starters for 3 phase circulators. 5) System Pump (P3) to be operated by zone relay or other installer supplied device. This diagram is for reference only. The installer or designer is responsible for the proper selection and design of the system. A6. Tankless Application Only with RTC - NO Building Heat; with and without storage tank (MECHANICAL) Boiler in HOT Standby Pel 120V (ac) ■ Class II Transformer 24V (aci Boiler in COLD Standby I ¡RTC) I A1 = Tankless Coil or Storage Tank Aquastat P1 = Boiler Circulator P2 = Tankless System Circulator R1 = Relay S1 = Boiler Return Sensor...
