8
The actuators with regulator ZP2RE5 are fitted with simpler controlled brakes
BR2. They are interconnected
with the regulator that provides impulse for action.
According to the electric motor output, corresponding variant is chosen:
BR2 550 of output up to 550 W,
BR 2.2
of output up to 2.2 kW.
If outputs higher than 2.2 kW are to be braked, electric motors of special version with an electromagnetic brake
should be used.
Switching of electric motor, contactor unit
The actuators in variants Control are fitted with built-in reversing contactor combinations. These are assembled
of two contactors and an over-current relay. The combination also includes mechanical blocking that prevents both
contactors from being closed at the same time. This could, for instance, happen in case of wrong connection of
jumpers on the terminal board. The blocking is not dimensioned for long-term action. The over-current relays protects
the electric motor against over-loading and is dimensioned with respect to its output.
According to the actuator version, the contactors are controlled by the regulator, change-over switch of local
control or external input. Control voltage is 230 V / 50 Hz as a standard; it is supplied via contacts of position and/or
moment micro-switches. Thus, these micro-switches need not be led out of the actuator.
The contactors used have a long mechanical service life and great reserve in switching ability; consequently, the electric
service life is also sufficient for particular use. The thermal relay is chosen so that it would reliably protect the electric motor
against overload. Set-up and outfit of the actuators provide for simple connection to power-supply and control circuits.
The power-supply circuits can be common for the whole group of actuators, which will save the cabling.
6. ELECTRIC PARAMETERS
External electric connection
a) Terminal board
The electric actuator is equipped with a terminal board for connection to external circuits. This terminal board uses
screw terminals allowing conductors with a maximum cross-section 4 mm
2
to be connected. Access to the terminal
board is obtained after removal of the terminal box cover. All control circuits of the electric actuator are brought out to
the terminal board. The terminal box is fitted with cable bushings for connecting the electric actuator. The electric motor
is fitted with an independent box with a terminal board and a bushing.
b) Connector
According to the customer's requirements the
MODACT MTN, MTP actuators can be fitted with the connector to
provide for connection of control circuits. This connector uses screw terminals allowing conductors with a maximum
cross-section 4 mm
2
to be connected. ZPA Pečky, a.s. also supplies a counterpart for the cable. In order to connect the
cable to this counterpart it is necessary to use special crimping pliers.
Actuator internal wiring
The internal wiring diagrams of the
MODACT MTN, MTP actuators with terminal designation are shown in this
Mounting and operating instructions.
Each actuator is provided with its internal wiring diagram on the inner side of the terminal box. The terminals
are marked on a self-adhesive label attached to a carrying strip under the terminal block.
Current rating and maximum voltage of microswitches
Maximum voltage of mikroswitches is 250 V AC as well as DC, at these maximum levels of currents.
MO, MZ
250 V AC / 2 A; 250 V DC / 0,2 A
SO, SZ
250 V AC / 2 A; 250 V DC / 0,2 A
PO, PZ
250 V AC / 2 A; 250 V DC / 0,2 A
The microswitches can only be used as single-circuit devices. Two voltages of different values and phases cannot
be connected to the terminals of the same microswitch.
Isolation resistance
Isolation resistance of electric control circuits against the frame and against each other is min. 20 M
Ω
. After a dump
test, isolation resistance of control circuits is min. 2 M
Ω
. Isolation resistance of the electric motor is min. 1.9 M
Ω
.
See Technical specifications for more details.
Electric strength of electric circuits isolation
Circuit of the resistance transmitter
500 V, 50 Hz
Circuit of the current transmitter
50 V DC
Circuits of microswitches and anti-condensation heater 1,500 V, 50 Hz
Electric motor
Un = 3 x 230/400 V
1 800 V, 50 Hz
