There is only ONE problem. The specifications did not specify AC . only 230V.
I do not know if that is their way of representing DC. Do NOT power this motor until you send an email or call them and ask if the 230V means DC or AC .
FYI-POWER = 150w /230v=0.65A current.
If it means DC, there is no problem reversing direction. If if means AC, there is no way to change direction.
COMMON sense dictates that if it is a LINEAR ACTUATOR, it MUST be capable of changing direction. When you email them make it clear you understand that and simply ask "Is it your policy to represent DC VOLTAGES WITHOUT the "dc" after the value and you want to confirm that is what they meant."
Assuming it is DC, then you need an H-BRIDGE to reverse direction
http://schematicdiagrams.net/basic-h-bridge-circuit-diagram.html
Attached are a couple of reference files as examples of h-Bridge circuits. Yours is not actually high power, simply high voltage. Big difference.
Since your initial post used relays, here is a link to an explanation of reversing motor direction using a double pole double throw relay ( DPDT)
The theory is simple.
Let's suppose we have a DPDT relay.
We'll call the first set of contacts (NO-1,NC-1,COM-1) SET-A
second set of contacts (NO-2,NC-2,COM-2) SET-B
Let's label the motor terminals "1" & "2"
Draw a circle to represent the motor and draw the two terminals horizonally with "1" on the left and "2" on the right.
Just to the left of the motor draw three small circles in a vertical column. Label the center circle COM. Label the top contact, NC
and the bottom contact "NO" (Normally Open)
Now draw the relay contact as a straight line from the center the NC and just past it to represent the relay in NC position.
Label the NC contact +V.. Label the NO contact -V. Do the same thing on the right side but with one difference. Draw the NC
contact as the BOTTOM RIGHT contact of the three vertical small circles and label it -V (minus V). Label the top RIGHT contact as
+V. You should now have motor term-1 connected to the left COM and the left contact in NC position at +V. On the right you should have motor term-2 connected to the right COM with the contact in NC position at the bottom right as -V. Now if you
engize the motor it turns one direction with term-1 as plus and 2 as minus. If you energize the relay it turns the other direction.
The drawback with this is the speed control must be done separately somehow. If using an H-bridge driver all those features are built in. With relay , you still have to add some other components for speed control
http://www.talkingelectronics.com/projects/H-Bridge/H-Bridge-1.html
I don't know how to do a high voltage H-Bridge with speed control other than to use discrete devices and choose the Mosfets for the correct voltage rating.
hbridge-reference-ualberta-arvp.pdf (406 KB)
MOSFETHBridge.pdf (579 KB)