anchor.diff:  	var/force_update = 0
   	var/update_state = -1
   	var/update_overlay = -1
  -
  +	var/icon_update_needed = FALSE
   
   /obj/machinery/power/apc/connect_to_network()
   	//Override because the APC does not directly connect to the network; it goes through a terminal.
  
positive.code: #define APC_UPOVERLAY_LOCKED 4096
  #define APC_UPOVERLAY_OPERATING 8192
  
  
  #define APC_UPDATE_ICON_COOLDOWN 200 // 20 seconds
  
  // the Area Power Controller (APC), formerly Power Distribution Unit (PDU)
  // one per area, needs wire conection to power network through a terminal
  
negative.code: // update the APC icon to show the three base states
  // also add overlays for indicator lights
  /obj/machinery/power/apc/update_icon()
  	var/update = check_updates() 		//returns 0 if no need to update icons.
  						// 1 if we need to update the icon_state
  						// 2 if we need to update the overlays
  	if(!update)
  		icon_update_needed = FALSE
  		return
  
  	if(update & 1) // Updating the icon state
  