What does separator dp (W) mean on a Kaeser Sigma Control?
Short answer: Oil separator clogged. If your Kaeser Sigma Control (original) is showing separator dp (W), the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
The oil separator element is clogged (high differential pressure). The documented remedy is changing the oil separator element.
Which machines show this?
first-generation Kaeser rotary screw compressors fitted with the original Sigma Control — the green-keypad, text-display controller Kaeser introduced around the turn of the 2000s on its direct-drive screw packages. This controller shows faults as short lower-case text messages with a severity letter: (A) for an alarm that shuts the machine down, (W) for a warning it keeps running through — so 'ADT (A)' is an airend-temperature shutdown while 'separator dp (W)' is a clogging separator flagged early. Alarms are acknowledged with the reset key after the cause is fixed. Practical tip: these machines also enforce a minimum start temperature of +3 °C, so a winter no-start in an unheated room is often the controller doing its job, not a fault.
What causes it?
- Oil separator element clogged — high differential pressure
- Element at the end of its service life
Can you fix it yourself?
As planning, yes — order the genuine element and schedule the change. Open the tank only after full shutdown and depressurization, and only if trained.
Step by step — what to try, in order:
- Order a genuine oil separator element and schedule the change.
- Only open the separator tank after full shutdown and depressurization, and only if trained.
When do you need a technician — and why?
The separator tank is a pressurized vessel; the element change belongs to a Kaeser service agent unless your crew is trained on the depressurization procedure.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does separator dp (W) mean on a Kaeser Sigma Control (original)?
Oil separator clogged. The oil separator element is clogged (high differential pressure). The documented remedy is changing the oil separator element.
Can I fix separator dp (W) on a Kaeser Sigma Control (original) myself?
As planning, yes — order the genuine element and schedule the change. Open the tank only after full shutdown and depressurization, and only if trained.
When does separator dp (W) on a Kaeser Sigma Control (original) need a technician?
The separator tank is a pressurized vessel; the element change belongs to a Kaeser service agent unless your crew is trained on the depressurization procedure. Have a Kaeser service agent change the element if you are not trained on the depressurization procedure.
Verified against service documentation: Kaeser Sigma Control (original) documentation for separator dp (W) (airsolcan.com)