Bell & Gossett P86271B Variable Speed NRF-VS Control with setpoint or external signal follower - Manual (Page 7)

POWER UP SEQUENCE
At initial power up, the NRF-VS will run at full speed for 5
seconds. It will then run at low speed for 5 seconds, before
adjusting to the appropriate speed. Monitor the pump at initial
power up. If the pump does not operate as indicated above,
the Gain (DIP Switch 4) can be adjusted to On (Fast) to
increase the minimum power setting.
OUTPUT LIGHTS
The NRF-VS cover has 6 LED lights to indicate operation and
faulty status.
THE GREEN OUTPUT LIGHT
Represents power to the NRF-VS. When constantly On, the
control is powered.
THE RED OUTPUT LIGHTS
Represent pump speed in increments of 20%. If only one Red
light is on, the pump speed is equal to or below 20%. If 2 Red
lights are On, the pump speed is equal to or below 40%.
When 3 Red lights are On, the pump speed is equal to or
below 60%. When 4 Red lights are On, the pump speed is
equal to or below 80%. When all Red lights are On, the pump
is running from 80% to full speed.
FLASHING LIGHTS
• This indicates an error in the input signal. If NRF-VS is set
to 4-20mA/2-10V, the signal must be below 0.5mA or
0.25V. Check input signal and wiring.
• If NRF-VS is set to Set Point, the sensor has fault status,
either shorted or opened. Check sensor wires and Ohm
reading against sensor temperature chart.
PERIODIC INSPECTION
Bell & Gossett products are designed to provide years of
trouble free service. It is recommended that periodic inspec-
tions be made to check for potential problems with the pump
and control. If any leakage or evidence of leakage is present,
repair or replace the unit.
TEMPERATURE Value
(in Degrees ºF) (in 0hms)
30 17264
35 14985
40 13040
45 11374
50 9944
55 8714
60 7653
70 5941
80 4649
90 3667
100 2914
110 2332
120 1879
130 1524
140 1243
150 1021
160 842
170 699
180 583
190 489
200 412
210 349
220 297
230 253
WARNING: The NRF-VS is an operating control only.
The boiler must have all safety and limit controls
required by code. It is the responsibility of the installer to
verify that all the safety and limits are working properly
before and after the NRF-VS is installed. Failure to follow
these instructions could result inserious personal injury,
death and/or property damage.
7
TEMPERA TURE
SENSOR CHART