Following successful installation and commissioning, final acceptance tests were carried out on the helium refrigerator for Wendelstein 7-X. The tests were carried out for the normal operating modes i.e. peak power mode (3.4 K), standard mode (3.9 K), short standby mode (< 10 K) and long standby mode (< 100 K). Besides the normal modes, the transient modes including, cool-down and warm-up, auto interchanging between various modes and the purging modes were tested. In addition, the handling of quench, emergency signals such as cryostat vacuum break, utility failure, alarm and trip signals were checked. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).