Bell & Gossett P86271B Variable Speed NRF-VS Control with setpoint or external signal follower - Manual (Page 2)

REQUIREMENTS
ELECTRICAL SAFETY
TYPICAL APPLICATIONS
WARNING: ELECTRICAL SHOCK HAZARD
Electrical connections are to be made by a qualified
electrician in accordance with all applicable codes, ordi-
nances and good practices. Failure to follow these instruc-
tions could result in serious personal injury, death and/or
property damage.
WARNING: ELECTRICAL GROUNDING HAZARD
Adequate electrical grounding is required for the safe
operation of B&G Pumps. The use of grounded metal con-
duit assures this requirement. If means of connection to the
supply – connection box (wiring compartment) is other than
grounded metal conduit, ground the pump back to the
service. Use a copper conductor at least the size of the
circuit connectors supplying the pump. Connect the ground
wire to the green grounding screw in the wiring compart-
ment. Failure to follow these instructions could result in
serious personal injury, death and/or property damage.
PRIMARY-SECONDARY WITH FAN COIL
PRIMARY
LOOP
Boiler
NRF-VS
Building
Management System
Boiler
Boiler
Sensor
NRF-VS
BYPASS BOILER INJECTION
Secondary Loop
Sensor
SECONDARY
LOOP NRF-VS
PRIMARY
LOOP Boiler
PRIMARY-SECONDARY INJECTION
SECONDARY
LOOP
PRIMARY
LOOP Boiler
PRIMARY-SECONDARY
NRF-VS
Variable Speed
Control or Building
Management System
2
DESCRIPTION
The NRF-VS is a variable speed control for use in hydronic
heating and cooling applications. The temperature of the
water is controlled by regulating the speed of the pump which
injects water from a different temperature water loop (Primary
loop) into a controlled loop (Secondary loop). As the speed of
the pump increases, more water is sent into the Secondary
loop, resulting in a secondary loop water temperature change.
The NRF-VS can be used either to receive an external 4-20mA
or 2-10V signal to control the pump speed. This allows the
control to regulate the pump speed to match the input signal
supplied.
The NRF-VS can also be used as a set point control. In this
mode of operation, the NRF-VS will control the pump speed to
hold a constant temperature (determined by the user) in the
Secondary loop. The NRF-VS is capable of reading the loop
temperature sensor. When used in a heating application, if
the loop temperature falls below an adjustable setting, the
NRF-VS will increase the speed of the injection pump.
In addition, the NRF-VS can be used in cooling applications. In
this senario, the NRF-VS wil increase pump speed whenever
the loop temperature increases above the setpoint.
OPERA TIONAL LIMITS
These controls are to be used on pumps designed to pump
liquids compatible with their cast iron, bronze or stainless
steel body constructions.
Maximum Operating Pressure: 150 PSI (10 bars).
Maximum Operating Temperature: 240ºF cast iron body,
230ºF brass and stainless steel body.
Electrical Rating: 115V, 60HZ, 1Ø.
Suitable for NRF, NBF, and SSF pumps with less than 1.1
amps pump nameplate rating.