Ошибка: Incorrect syntax near '('

CREATE PROCEDURE [Proc].[prog];
                @YearTA nvarchar(2) = N'0'--int=0   
,               @ParPlant nvarchar(2) = N''
,               @ParUnit nvarchar(40)=N''
,               @ParTypeEq nvarchar(40)=N''
        
                                    
AS
--SET DATEFORMAT DMY
 
DECLARE @ALLequip_wherestr nvarchar(4000)
DECLARE @output nvarchar(4000)
 
SET @ALLequip_wherestr = N''
 
IF (SELECT LEN(@ParPlant)) > 0
BEGIN 
    SET @ALLequip_wherestr = @ALLequip_wherestr + N' AND '+@ParPlant+''
END
 
IF (SELECT LEN(@ParUnit)) > 0
BEGIN 
    SET @ALLequip_wherestr = @ALLequip_wherestr + N' AND '+@ParUnit+''
END
 
IF (SELECT LEN(@ParTypeEq)) > 0
BEGIN 
    SET @ALLequip_wherestr = @ALLequip_wherestr + N' AND '+@ParTypeEq+''
END
 
SET @output =N'
SELECT
    '''' as Ch    
,   e.EquipID
,   p.PlantName as Plant 
,   u.UnitName  as Unit
,   e.UserEquipID as Equipment
,   f.FixedEquipType as Type
,   CASE WHEN (e.ERP_Asset_Field4 IS NULL) THEN u.Type ELSE e.ERP_Asset_Field4 END AS Inspts
,   case when (wl.EquipID is null) then ''0'' else ''1'' end as incld
,   wl.YearTA
FROM Equipment AS e INNER JOIN Unit AS u ON e.UnitID = u.UnitID INNER JOIN
     Plant AS p ON e.PlantID = p.PlantID INNER JOIN
     FixedEquipmentAsset AS f ON e.EquipID = f.EquipID left join
     (SELECT  EquipID, YearTA, Opportunity, TA
        FROM  TCO_Data.WL
        GROUP BY EquipID, YearTA
        HAVING YearTA ='+@YearTA+') as wl on wl.EquipID=e.EquipID
        WHERE p.plantid<>48 and f.ActiveFlag = ''y''
        group by e.EquipID, p.PlantName, u.UnitName, e.UserEquipID,e.ERP_Asset_Field4, u.Type,  
         f.FixedEquipType, wl.EquipID'
 
 
+@ALLequip_wherestr 
    
    EXEC sp_executesql @output
 
GO