Page 64
B
RADFORD
W
HITE
9.10
Variable speed pump control (VSPC)
is standard equipment on all BMGH boilers. Pump
speed is controlled to maintain a user-chosen
temperature rise between the inlet and outlet of the
MagnaTech.
General PCB Operation
1. The desired Delta T can be set to any of the
following values by moving or adding jumpers to the
JP2 terminal on the control: See Figure 35
-15 deg F/8 deg C
-20 deg F/10 deg C
-25 deg F/13 deg C
-30 deg F/ 16 deg C
By adding a second jumper, one on “15 deg F” and
one on “20 deg F”, it is possible to achieve 35 deg F
/19 deg C.
By adding a second jumper, one on “15 deg F” and
one on “25 deg F”, it is possible to achieve 40 deg
F/22 deg C.
2. As shipped, the VSPC has a jumper on the JP4
terminal, to operate a 0-10 VDC output. If a 4-20
mA output is needed, move the jumper to the JP5
terminal. Figure 35
3. Variable speed pump control can operate in
°
F
or
°
C. A jumper on the JP1 terminal allows the user
to choose the temperature scale.
4
If Main Gas valve is “OFF” AND a call for heat
is “TRUE” then the PCB overrides the PID control
and runs the pump output at 100% (10 VDC, or 20
mA).
5. Once the Main Gas valve is energized the PCB
will maintain pump output at 100% for 60 seconds
to allow the system to stabilize. Once the 60 second
timer has expired, the PCB will then run the pump
output speed based on the jumper setpoint. .
6. When “T-T” is satisfied, the PCB will run pump
at 100% output for the duration of the pump overrun
time.
7. A jumper on the “JP1” terminal on the VSPC
PCB will allow the Variable speed pump control to
operate in degrees Fahrenheit or Celsius. (Factory set
for Fahrenheit).
8. The VSPC PCB has a low end cap to prevent
nuisance low flow trips. The cap is factory
programmed to 2 VDC.
9. Factory settings are:
-Degrees - Fahrenheit
-Output Signal- 0 -10VDC
-Delta T setpoint - 30
°
F/17
°
C
2
6
4-20MA(-)
4-20MA(+)
0-10VDC(+)
0-10VDC(-)
N/C
COM
N/O
TB2
TB5
TB4
TB1
TB6
PCB
DIGITIZED
P/N E2345200
LED1
1
2
3
4
1
2
3
4
1
2
3
4
TB3
JP1
7&8 = F
1&2 = SPARE JUMPER
JP2
1&2 = 15 DEG F / 8 DEG C
3&4 = 20 DEG F / 10 DEG C
5&6 = 25 DEG F / 13 DEG C
7&8 = 30 DEG F / 16 DEG C
JP5
JP4
JP3
1
2
3
4
1
2
3
2
4
6
8
1
3
5
7
1
3
5
7
2
4
6
8
+24V
-24V
10K
INLET
SENSOR
10K
OUTLET
SENSOR
NOTE(S)
1.PURCHASED FROM DIGITIZED COMM. INC.
SERIAL NO. DC1002713
FIRMWARE SETTINGS
P = 20
I = 10
D = 0
ANTI RESET WINDUP = 600
CONTROL ERROR = 70
1
2
DWG NO.
E23452
SH
1
REV
A
AL 1-10-14
REVISIONS
REV.
CHANGE:
APPR
ENGR APPR
ECN
DRAFT
CHECK
UPDATED DRAWING PER SKETCH FROM LAB
A
14-002N-08
SM 1-10-14
SCALE: NONE
INTENDED SIZE:
SOFTWARE DWG. NO:
C
SHEET 1 OF 1
REV.
APPROVALS
DRAFT
ENGR
APPR
UNLESS OTHERWISE SPECIFIED:
DO NOT SCALE DRAWING.
THIRD ANGLE PROJECTION.
DIMENSIONS ARE IN INCHES.
TOLERANCES ARE:
MATERIAL:
FINISH
CJT 12/2/11
S
DECIMALS .X .1
DECIMALS .XX .03
DECIMALS .XXX .010
ANGLES 1
TITLE:
FRACTIONS 1/8"
DIGITIZED PRINTED CIRCUIT
BOARD
E23452
A
Figure 35. VSPC Digital Circuit Board