Application Brochure

© 2013 284_A - 02/13 8 of 12
S1 = Outdoor Sensor
S2 = Boiler Supply Sensor
S3 = Boiler Return Sensor
S4 = DHW Sensor
S5 = Boiler Inlet Sensor
S6, S7 = Boiler Outlet Sensors
S8 = Vent Sensor
P1 = Primary Pump
P2, P3 = Boiler Pumps
P4 = IDHW Pump
Application A 284-4 Mechanical
Description
Two modulating condensing boilers are operated to provide heat for space heating and indirect DHW loads. The boiler target
temperature for the space heating load is determined from outdoor temperature reset and indoor temperature feedback
provided by tekmarNet
®
thermostats.
Concept Drawing: This is only a concept drawing, not an engineered drawing. It is not intended to describe a complete system, nor any particular system. It is up to the
system designer to determine the necessary components for and configuration of the particular system being designed, including additional equipment, isolation relays
(for loads greater than the control’s specified output ratings), and any safety devices which in the judgement of the designer are appropriate, in order to properly size,
configure and design that system and to ensure compliance with building and safety code requirements.
Features:
The boiler plant is sequenced to obtain maximum efficiency based on the boiler types & target temperatures. For detailed
information about sequencing, rotation & staging, refer to the 284_D Installation & Operation Manual.
Outdoor Temperature Reset saves energy by operating the boiler plant using the lowest possible temperatures. Lower
water temperatures ensure modulating condensing boilers operate at maximum efficiency.
Indoor Temperature Feedback compensates for heat loss or gain caused by the sun, appliances or occupant activity to
improve system efficiency, comfort & response time.
Optional indirect DHW (IDHW) priority.
Boiler ∆T monitoring is available when using optional boiler outlet sensors (S6 & S7) and boiler inlet sensor (S5).
Remote access options are available through the tN4 Gateway 482 or 483.
The sensor required to support vent temperature sensing (S8) is scheduled for a future release.
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482 / 483
tekmarNet
®
4
S8
S2
S3
S5
S6
P2 P3
P4
P1
284
S1
tekmarNet
®
Thermostats
tN2 Wiring
Center 313
S7
S4
ENABLE (1) = AUTO
CONDENSE (1) = YES
Boil TYPE (1) = MOD
ENABLE (2) = AUTO
CONDENSE (2) = YES
Boil TYPE (2) = MOD
ENABLE (3) = OFF
ENABLE (4) = OFF
Essential Source (#) Settings:
APP MODE = RSET
PUMP 1 = AUTO
PUMP 2 = OFF
IDHW MODE = ON
IDHW LOCATION = Boil
IDHW SENSOR = ON
IDHW PRIM PUMP = OFF
Essential System Settings:
Legend DIP Settings:
External Flow Proof / Off
External C.A. Proof / Off
Off / Exercise
Setback / Off