Achieve-a-tron

Arcane Annihilator is a fast casting, interruptable spell.

Static Shock occurs only as a result of Electron being struck while Unstable Shield is active.

Poison Bomb requires that those who are fixated by the bombs kite them away from other raid members so they can be safely killed by ranged DPS.

Flamethrower requires that a raid member turns Magmatron away from the rest of the group when they're marked with Acquiring Target.

EDIT: Why must people needlessly downrate things?

Remember: You will not have to complete all 4 parts of this achievement at the same time! It's possible to complete this achievement over several lockouts
The fight starts out with 1 construct active. The second one will then activated as the first constructs' energy bar, depletes to 50.
So remember that the fight requires you to be aware of several parts of this post at once, even though they are described as separate encounters. I'd recommend doing only 1 part of the achievement per kill, even though all 4 parts are manageable to pull off in 1 kill, It might just take some extra time.

It's split up into 4 different (read : separate) parts.
No player hit by Static Shock - Static Shock is a spell cast by Electron'sUnstable shield. He will cast his own variation of the shield ability (Unstable shield) just like the other 3 constructs, when he reaches 50 energy (he'll start at 100, and then slowly drain). The part of this achievement, is completed by making sure that Electron won't get hit, while his shield remains active.
Protip: If you're going for this part of the achievement, please make sure that dots are 100% off Electron, as they'll trigger the shield, and cause him to cast the Static Shock. The tank should stop attacking the second he starts casting the shield.

No player hit by Poison Bomb - "Poison Bombs" is a part of Toxitron' spell rotation.
The key to completing this part is very simple however! Toxitron will cast a spell from time to time, called Poison Protocol.
When he casts this spell Poison Protocol, simply move away from him! Tanks, Melees and Ranged have to stay at distance, as he will spawn 3 Poison Bombs, that'll explode if they hit their designated target. The target is set by a random function (Fixate) as they spawn, so having a ranged DPS at distance, assigned to call out the targets of the poison adds, is a very helpful thing to do.
The healthpool of the adds happens to be really low, so a few direct damage spells will do the job.
You will get this part of the achievement, as long as none of the adds actually makes it all the way to their designated target.
Protip: The Poison Bombs are stun/slowable.

No player hit by Arcane Annihilator - Arcane Annihilator is a spell casted by our best friend Arcanotron. This part is easily the hardest. Arcane Annihilator is an interuptable-cast, that will deal direct magic damage, to Arcanotron's current target. The key to this part is to have 2 interrupters interupt him from the exact second he activates, till the second he shuts down.
You want 2 interrupters on him, because he'll cast the spell way more often than every 10 seconds (Making it impossible for a single guy to interrupt, as most interrupts have around 10 seconds cooldown).
Protip: Having a tank as one of the interupters, will be a massive benfit, as he's able to cast Arcane Annihilator, right after he activates, making a DPS very likely to grab aggro when taking interrupting the first cast if you're in a group with a slow tank. You will have to be very good at interupting him, as 1 fail-interupt will make you fail the achievement. He will still cast his Arcane Annihilator while his shield is active, so the interrupters will have to sit at him all the time.
I got a quick tip from the poster beneath me. An elemental Shaman is able to solo interrupt it, as Wind shear with theReverberation talent, can solo interrupt it! Thanks to WarlockLover for the tip!

No more than one player hit by each Flamethrower - Magmatron's Flamethrower is triggered by the Acquiring Target ability. Acquiring Target is cast on a random raid member (from personal experience, we haven't seen any melees or tanks getting targeted).
The key to this part is to make sure that everyone's spread out, as the Flamethrower ability is a line of fire, going from the boss to the raid member that's been Acquired as Magmatron's target. The achievement fails if there are more people than the Acquired target getting hit by the line of fire.
Protip: Use your brain! If you see a guy next to you with a big cross over the head, move the hell away from him!

If you need more Protips, feel free to ask me - Horseofdeath - Darksorrow - Alliance - EU

This achievment can be completed over multiple victories against the Omnitron Defense!