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English (US)
3.3.2 Signal-cable connection
ALPHA2 26-99 pumps are internally speed-
controlled and have no active signal-cable
connection. It is covered by a blanking plug.
0-10 VDC
ALPHA1 26-99 circulator pumps are externally
speed-controlled by an analog 0-10 VDC signal.
To enable pump control, a signal cable is
required.
The signal cable has two or three conductors.
The signal cable must be connected to the
control box by a dubox housing with an FCI
terminal block and terminals.
Fig. 4
VDC signal cable connection
4. Starting up the product
•
The pump may stop when the inspection
screw is loosened.
•
When the pump is connected to power the
pump starts automatically either on the
preset control mode or the last stored setting
(AUTO) or with the speed that refers to the
external control signal (VDC).
•
Without signal, the pump will run at
maximum speed (profile heating).
•
In special systems (e.g. with check valve at
the top of the pump), it might be necessary
to check if the system has been vented
completely by opening the inspection screw
in the middle of the nameplate.
WARNING
Electric shock
Death or serious personal injury
- The pump must be connected to an
external main switch with a
minimum contact gap of 0.12
inches (3 mm) in all poles.
- Grounding or neutralization must
be used for protection against
indirect contact.
WARNING
Electric shock
Death or serious personal injury
- External signal cables must be in
accordance with chapter 725 of the
NEC in order to insulate this circuit
from others. The suitable type of
signal cable is type CL3, CL3R,
CL3P or equivalent.
Do not connect the signal-reference
wire to the ground.
Connect the signal wires to the
correct poles. Otherwise the pump
might be damaged.
TM
0
7
0
352
0
518
Black: Signal output (optional)
Blue: Signal reference
Brown: Signal input
Plug
CAUTION
Hot liquid
Minor or moderate personal injury
- When loosening the inspection
screw, be aware of hot, spraying
water.
Flush the system of debris before
installation.
The pump must not run dry.
The required minimum inlet pressure
must be available at the pump inlet.
Do not start the pump until the system
has been filled with liquid and vented.
The pump is self-venting, and does
not need to manually be vented
before startup.
The system cannot be vented through
the pump.
Air in the pump may cause noise. This
noise ceases after a few minutes of
running.
Air inside the pump will be transported
by the medium into the system during
the first minutes after pump startup.
