Xylem Bell & Gossett ecocirc XL Series Instruction Manual page 11

5 System Description
The night mode is active only in combination with:
• Proportional pressure
• Constant pressure
• Fixed speed
This function reduces power consumption of the pump to the minimum
when heating system is not running. An algorithm detects the water
temperature change and automatically adjusts the speed of the pump.
The pump returns to the original set point as soon as the system re-
starts.
5.2.3 ∆p-T control
This function adjusts the nominal differential pressure set point accord-
ing to the temperature of the pumped media.
For details refer to the electronic drive manual on www.bellgos-
sett.com
5.2.4 T-Constant temperature control
This functional mode changes the speed of the pump in order to main-
tain a constant temperature of the pumped media. It is suitable for
heating systems with fixed system characteristics, for example Domes-
tic Hot Water Systems.
For details, refer to the electronic drive manual on www.bellgos-
sett.com
5.2.5 ∆T constant
This function alters the speed of the pump in order to maintain a con-
stant differential temperature of the pumped media.
For details, refer to the electronic drive manual on www.bellgos-
sett.com
5.2.6 External start/stop
The pump can be started or stopped via an external dry contact or a
relay that is connected to terminals 11 and 12 on single phase pump
models. The pump unit is provided by default, with the terminals 11
and 12 jumpered. See Figure 6 on page 8.
Start/stop terminals for three phase models are 13 and 14. See figure 7
on page 8.
NOTICE:
• The pump provides 5 VDC through the start / stop terminals.
• No external voltage must be provided to start / stop terminals.
• The cables connected to terminals 11 and 12 on single phase or to
terminals 13 and 14 on three phase pumps shall not exceed 65 feet
in length
5.2.7 Analog Input
The pump integrates a 0-10 V analog input at terminals 7 and 8 for sin-
gle phase and 19 and 20 for three phase units. See Figures 6 and 7 on
page 8.
When a voltage input is detected, the pump switches to fixed speed
control mode automatically and starts to run according to the following
diagram:
SPEED
RPM
SPEED VARIATIONS WITH INCREASING control voltage [V]
MAX
SETPOINT
MIN
STOP
0 0.6 0.9V 1.5 Vset
Figure 10: Voltage input detected
0–0.6V Voltage control — un-
recognized
10
10 [V]
0.6–0.9V Control recognized —
fixed speed icon be-
gins blinking. Pump
off.
0.9–1.5V Pump operates at min-
imum speed
1.5–10V Pump accelerates at
controlled speed
SPEED
RPM
SPEED VARIATIONS WITH DECREASING control voltage [V]
MAX
SETPOINT
MIN
STOP
0 0.6 1.2 1.5 Vset
Figure 11: Voltage input detected
10–1.5V Pump decelerates at
controlled speed
1.5–1.2V Pump runs at mini-
mum speed
1.2–0.6V Control recognized —
fixed speed icon re-
mains blinking. Pump
off.
0.6–0V Voltage control — un-
recognized
5.2.8 Signal relay
Dry relay contacts are available at terminal 4 and 5 for single phase
pumps, and at terminals 22, 23 and 24, 25 for three phase pumps.
Relay ratings
1. Vmax < 250 VAC
2. Imax < 2 A
5.2.8.1 Signal relay for single phase pumps
A dry contact relay is provided at terminals 4 and 5. See connection di-
agram, figures 6 and 7 on page 8, for location. If there is a fault, the re-
lay contact closes to display a red status light and the error code on the
user interface display. See User interface
closure can also be used to energize a remote fault display.
5.2.8.2 Signal relay for 3–phase pumps
Two normally open relay contacts are available at terminals 22, 23 and
24, 25. If an error causes the pump to stop operating, the relay contact
closes and terminals 24–25 are closed. Terminals 23–24 indicate pump
stop/run status.
Table 1: Relay status
Motor running
No fault Relay 1 Open (24-25
open circuit)
Relay 2 Closed (22-23
short circuit)
10 [V]
on page 9. The relay contact
Motor stopped
Relay 1 Open (24-25
open circuit)
Relay 2 Open (22-23
open circuit)
ecocirc ® XL INSTRUCTION MANUAL