ATS output fails when the power switching from CEB to Generator

[Anonymous user]

ATS model is AP7723

log

03/15/2018	22:42:14	Automatic Transfer Switch: Fault cleared on Source A.
03/15/2018	22:42:13	Automatic Transfer Switch: Redundancy has been restored. Source A is available.
03/15/2018	22:41:59	Automatic Transfer Switch: Fault exists on Source A.
03/15/2018	22:41:52	Automatic Transfer Switch: ATS has switched source. Source A is current source.
03/15/2018	22:41:42	Automatic Transfer Switch: ATS has lost redundancy. Source A is not available.
03/15/2018	22:41:42	Automatic Transfer Switch: ATS has switched source. Source B is current source.
03/15/2018	22:40:46	Automatic Transfer Switch: ATS has switched source. Source A is current source.
03/15/2018	22:40:14	Automatic Transfer Switch: ATS has switched source. Source B is current source.
03/15/2018	22:40:05	Automatic Transfer Switch: Fault cleared on Source A.
03/15/2018	22:40:04	Automatic Transfer Switch: Redundancy has been restored. Source B is available.
03/15/2018	22:39:57	Automatic Transfer Switch: Fault cleared on Source B.
03/15/2018	22:39:50	Automatic Transfer Switch: Fault exists on Source A.
03/15/2018	22:39:41	Automatic Transfer Switch: Fault exists on Source B.
03/15/2018	22:39:34	Automatic Transfer Switch: ATS has lost redundancy. Source B is not available.
03/15/2018	22:39:05	Automatic Transfer Switch: Fault cleared on Source B.
03/15/2018	22:39:02	Automatic Transfer Switch: Redundancy has been restored. Source B is available.
03/15/2018	22:38:44	Automatic Transfer Switch: Fault exists on Source B.
03/15/2018	22:38:38	Automatic Transfer Switch: ATS has lost redundancy. Source B is not available.
03/15/2018	22:38:18	Automatic Transfer Switch: Over frequency violation cleared on Source B.
03/15/2018	22:38:07	Automatic Transfer Switch: Over frequency violation on Source B.
03/15/2018	22:27:31	Automatic Transfer Switch: ATS Communication established.
03/15/2018	22:27:11	Automatic Transfer Switch: 7-Segment display hardware initialized.
03/15/2018	22:27:11	Automatic Transfer Switch: Phase Leds/Push-button hardware initialized.
03/15/2018	22:27:00	System: Network service started. System IP is 198.18.130.38 from manually configured settings.
03/15/2018	22:27:00	System: Coldstart.
03/15/2018	20:55:37	Automatic Transfer Switch: Fault cleared on Source B.
03/15/2018	20:55:36	Automatic Transfer Switch: Fault cleared on Source A.
03/15/2018	20:55:35	Automatic Transfer Switch: Redundancy has been restored. Source B is available.
03/15/2018	20:55:22	Automatic Transfer Switch: Fault exists on Source B.
03/15/2018	20:55:21	Automatic Transfer Switch: Fault exists on Source A.
03/15/2018	20:55:03	Automatic Transfer Switch: ATS has switched source. Source B is current source.
03/15/2018	20:55:01	Automatic Transfer Switch: ATS has lost redundancy. Source B is not available.
03/15/2018	20:52:09	Automatic Transfer Switch: ATS has switched source. Source A is current source.
03/15/2018	20:51:58	Automatic Transfer Switch: ATS has switched source. Source B is current source.
03/15/2018	20:48:15	Automatic Transfer Switch: Fault cleared on Source B.
03/15/2018	20:48:13	Automatic Transfer Switch: Fault cleared on Source A.
03/15/2018	20:48:12	Automatic Transfer Switch: Redundancy has been restored. Source B is available.
03/15/2018	20:48:04	Automatic Transfer Switch: Fault exists on Source B.
03/15/2018	20:48:02	Automatic Transfer Switch: Fault exists on Source A.
03/15/2018	20:47:40	Automatic Transfer Switch: ATS has lost redundancy. Source B is not available.
03/15/2018	20:46:23	Automatic Transfer Switch: Redundancy has been restored. Source B is available.
03/15/2018	20:46:16	Automatic Transfer Switch: Fault cleared on Source B.
03/15/2018	20:46:09	Automatic Transfer Switch: Over frequency violation cleared on Source B.
03/15/2018	20:46:09	Automatic Transfer Switch: Fault exists on Source B.
03/15/2018	20:45:50	Automatic Transfer Switch: ATS has lost redundancy. Source B is not available.
03/15/2018	20:45:43	Automatic Transfer Switch: Over frequency violation on Source B.

Please tell why this is happening