Belimo EFB Series Wiring page 2

Wiring for Damper Actuators and Control Valves
General Wiring Instructions
WARNING: The wiring technician must be trained and experienced
with electronic circuits. Disconnect power supply before attempting any
wiring connections or changes. Make all connections in accordance
with wiring diagrams and follow all applicable local and national codes.
Provide disconnect and overload protection as required. Use copper,
twisted pair, conductors only. If using electrical conduit, the attachment
to the actuator must be made with fl exible conduit.
Always read the controller manufacturer's installation
literature carefully before making any connections.
instructions in this literature. If you have any questions, contact
the controller manufacturer and/or Belimo.
Transformer(s)
Belimo actuators require a 24 VAC Class 2 transformer. The
actuator enclosure cannot be opened in the fi eld, there are no
parts or components to be replaced or repaired.
– EMC Directive: 2004/108/EC
– Software Class A: Mode of Operation Type 1
– Low Voltage Directive: 2006/95/EC
Example: 3 AF Actuators Supplied, 16 Ga. wire (refer to table on
page 3)
350 ft. (allowable wire length) ÷ 3 actuators = 117 ft. maximum wire run
Typical Transformer Sizing
Actuator Series Voltage
EFB, EFX
AFB, AFX
AF
NFB, NFX
LF
TF
GMB
AMB / ARB
NMB
LMB / LRB
CMB
AHB
LHB
LUB
AMQB
NMQB
LMQB
AHQB
LHQB
GK / GKR
NK
AHK
800-543-9038 USA
2
Follow all
Required VA
Per Actuator
24 16
24 10
24 10
24 9
24 7
24 5
24 7
24 6
24 6
24 3
24 1.5
24 4.5
24 3
24 3
24 26
24 23
24 23
24 23
24 23
24 21
24 22
24 20
CAUTION: It is good practice to power electronic or digital controllers
from a separate power transformer than that used for actuators or other
end devices. The power supply design in our actuators and other end
devices use half wave rectifi cation. Some controllers use full wave
rectifi cation. When these two different types of power supplies are
connected to the same power transformer and the DC commons are
connected together, a short circuit is created across one of the diodes in
the full wave power supply, damaging the controller. Only use a single
power transformer to power the controller and actuator if you know the
controller power supply uses half wave rectifi cation.
Multiple actuators, one transformer
Multiple actuators may be powered from one transformer provided the
following rules are followed:
1. The TOTAL current draw of the actuators (VA rating) is less than or
equal to the rating of the transformer.
2. Polarity on the secondary of the transformer is strictly followed.
This means that all No. 1 wires from all actuators are connected
to the common leg on the transformer and all No. 2 wires from all
actuators are connected to the hotleg. Mixing wire No. 1 & 2 on one
leg of the transformer will result in erratic operation or failure of the
actuator and/or controls.
Multiple actuators, multiple transformers
Multiple actuators positioned by the same control signal may be powered
from multiple transformers provided the following rules are followed:
1. The transformers are properly sized.
2. All No. 1 wires from all actuators are tied together and tied to the
negative leg of the control signal. See wiring diagram.
Wire type and wire installation tips
For most installations, 18 or 16 Ga. cable works well with Belimo
actuators. Review job requirements and determine whether a plenum
or appliance rated cable is appropriate. Use code-approved wire nuts,
terminal strips or solderless connectors where wires are joined. It is
good practice to run control wires unspliced from the actuator to the
controller. If splices are unavoidable, make sure the splice can be
reached for possible maintenance. Tape and/or wire-tie the splice to
reduce the possibility of the splice being inadvertently pulled apart.
Wire length for actuator installation
Keep power wire runs below the lengths listed in the following tables.
If more than one actuator is powered from the same wire run, divide
the allowable wire length by the number of actuators to determine the
maximum run to any single actuator.
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