diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/alarm/alarms-table-widget.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/alarm/alarms-table-widget.component.ts
index 034c131769..098f9a0939 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/alarm/alarms-table-widget.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/alarm/alarms-table-widget.component.ts
@@ -888,12 +888,22 @@ export class AlarmsTableWidgetComponent extends PageComponent implements OnInit,
       $event.stopPropagation();
     }
     if (this.alarmsDatasource.selection.hasValue()) {
-      const alarmIds = this.alarmsDatasource.selection.selected.filter(
-        (alarmId) => alarmId !== NULL_UUID
+      const unacknowledgedAlarms = this.alarmsDatasource.selection.selected.filter(
+        (alarm) => alarm.id.id !== NULL_UUID && (alarm.status === AlarmStatus.CLEARED_UNACK ||
+          alarm.status === AlarmStatus.ACTIVE_UNACK)
       );
-      if (alarmIds.length) {
-        const title = this.translate.instant('alarm.aknowledge-alarms-title', {count: alarmIds.length});
-        const content = this.translate.instant('alarm.aknowledge-alarms-text', {count: alarmIds.length});
+      let title = '';
+      let content = '';
+      if (!unacknowledgedAlarms.length) {
+        title = this.translate.instant('alarm.selected-alarms', {count: unacknowledgedAlarms.length});
+        content = this.translate.instant('alarm.selected-alarms-are-acknowledged');
+        this.dialogService.alert(
+          title,
+          content
+        ).subscribe();
+      } else {
+        title = this.translate.instant('alarm.aknowledge-alarms-title', {count: unacknowledgedAlarms.length});
+        content = this.translate.instant('alarm.aknowledge-alarms-text', {count: unacknowledgedAlarms.length});
         this.dialogService.confirm(
           title,
           content,
@@ -901,16 +911,14 @@ export class AlarmsTableWidgetComponent extends PageComponent implements OnInit,
           this.translate.instant('action.yes')
         ).subscribe((res) => {
           if (res) {
-            if (res) {
-              const tasks: Observable<AlarmInfo>[] = [];
-              for (const alarmId of alarmIds) {
-                tasks.push(this.alarmService.ackAlarm(alarmId));
-              }
-              forkJoin(tasks).subscribe(() => {
-                this.alarmsDatasource.clearSelection();
-                this.subscription.update();
-              });
+            const tasks: Observable<AlarmInfo>[] = [];
+            for (const alarm of unacknowledgedAlarms) {
+              tasks.push(this.alarmService.ackAlarm(alarm.id.id));
             }
+            forkJoin(tasks).subscribe(() => {
+              this.alarmsDatasource.clearSelection();
+              this.subscription.update();
+            });
           }
         });
       }
@@ -944,12 +952,22 @@ export class AlarmsTableWidgetComponent extends PageComponent implements OnInit,
       $event.stopPropagation();
     }
     if (this.alarmsDatasource.selection.hasValue()) {
-      const alarmIds = this.alarmsDatasource.selection.selected.filter(
-        (alarmId) => alarmId !== NULL_UUID
+      const activeAlarms = this.alarmsDatasource.selection.selected.filter(
+        (alarm) => alarm.id.id !== NULL_UUID && (alarm.status === AlarmStatus.ACTIVE_ACK ||
+          alarm.status === AlarmStatus.ACTIVE_UNACK)
       );
-      if (alarmIds.length) {
-        const title = this.translate.instant('alarm.clear-alarms-title', {count: alarmIds.length});
-        const content = this.translate.instant('alarm.clear-alarms-text', {count: alarmIds.length});
+      let title = '';
+      let content = '';
+      if (!activeAlarms.length) {
+        title = this.translate.instant('alarm.selected-alarms', {count: activeAlarms.length});
+        content = this.translate.instant('alarm.selected-alarms-are-cleared');
+        this.dialogService.alert(
+          title,
+          content
+        ).subscribe();
+      } else {
+        title = this.translate.instant('alarm.clear-alarms-title', {count: activeAlarms.length});
+        content = this.translate.instant('alarm.clear-alarms-text', {count: activeAlarms.length});
         this.dialogService.confirm(
           title,
           content,
@@ -957,16 +975,14 @@ export class AlarmsTableWidgetComponent extends PageComponent implements OnInit,
           this.translate.instant('action.yes')
         ).subscribe((res) => {
           if (res) {
-            if (res) {
-              const tasks: Observable<AlarmInfo>[] = [];
-              for (const alarmId of alarmIds) {
-                tasks.push(this.alarmService.clearAlarm(alarmId));
-              }
-              forkJoin(tasks).subscribe(() => {
-                this.alarmsDatasource.clearSelection();
-                this.subscription.update();
-              });
+            const tasks: Observable<AlarmInfo>[] = [];
+            for (const alarm of activeAlarms) {
+              tasks.push(this.alarmService.clearAlarm(alarm.id.id));
             }
+            forkJoin(tasks).subscribe(() => {
+              this.alarmsDatasource.clearSelection();
+              this.subscription.update();
+            });
           }
         });
       }
@@ -1124,7 +1140,8 @@ class AlarmsDatasource implements DataSource<AlarmDataInfo> {
   private alarmsSubject = new BehaviorSubject<AlarmDataInfo[]>([]);
   private pageDataSubject = new BehaviorSubject<PageData<AlarmDataInfo>>(emptyPageData<AlarmDataInfo>());
 
-  public selection = new SelectionModel<string>(true, [], false);
+  public selection = new SelectionModel<AlarmDataInfo>(true, [], false,
+    (alarm1: AlarmDataInfo, alarm2: AlarmDataInfo) => alarm1.id.id === alarm2.id.id);
 
   private selectionModeChanged = new EventEmitter<boolean>();
 
@@ -1202,7 +1219,7 @@ class AlarmsDatasource implements DataSource<AlarmDataInfo> {
     }
     if (this.selection.hasValue()) {
       const alarmIds = alarms.map((alarm) => alarm.id.id);
-      const toRemove = this.selection.selected.filter(alarmId => alarmIds.indexOf(alarmId) === -1);
+      const toRemove = this.selection.selected.filter(alarm => alarmIds.indexOf(alarm.id.id) === -1);
       this.selection.deselect(...toRemove);
       if (this.selection.isEmpty()) {
         isEmptySelection = true;
@@ -1276,14 +1293,14 @@ class AlarmsDatasource implements DataSource<AlarmDataInfo> {
 
   toggleSelection(alarm: AlarmDataInfo) {
     const hasValue = this.selection.hasValue();
-    this.selection.toggle(alarm.id.id);
+    this.selection.toggle(alarm);
     if (hasValue !== this.selection.hasValue()) {
       this.onSelectionModeChanged(this.selection.hasValue());
     }
   }
 
   isSelected(alarm: AlarmDataInfo): boolean {
-    return this.selection.isSelected(alarm.id.id);
+    return this.selection.isSelected(alarm);
   }
 
   clearSelection() {
@@ -1304,7 +1321,7 @@ class AlarmsDatasource implements DataSource<AlarmDataInfo> {
           }
         } else {
           alarms.forEach(row => {
-            this.selection.select(row.id.id);
+            this.selection.select(row);
           });
           if (numSelected === 0) {
             this.onSelectionModeChanged(true);