Download  Print this page

Outside Air Damper Fan Coils ("economizer", Fnc10, Fnc12) - Siemens Desigo RXB Technical Manual

Technical manual.
Hide thumbs
   
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476

Advertisement

Enabling the function
Control sequence,
damper actuator
Siemens
Building Technologies
The following conditions must be fulfilled:
– The room controller must be in Comfort mode
– The radiator must not be disabled (e.g. by application mode = COOL).
8.6
Outside air damper fan coils ("Economizer",
FNC10, FNC12)
The outside air damper mainly serves to provide the room with fresh outside air. In
addition, the outside air can be used to cool the room.
The outside air damper is always operated in Comfort and Precomfort modes.
In Economy mode, it is operated only in conjunction with the following special functions
(see page 128 ff. for a description):
Pre-Cool, Free Cool, Night Purge and Fan-Only.
The damper is controlled through a stroke model calculated from the runtime of the
actuator.
The Economizer setpoint Outside air temp. min. damper pos. defines at which outside
temperature the outside air damper is opened to an adjustable minimum position.
This minimum position ensures a constant air supply below the outside air temperature.
The Outside air temp. min. damper pos. setpoint should be selected to ensure that
there is at least a difference of 4 K between this value and the cooling setpoint and that,
at the same time, no draught is caused by the inflow of cold outside air.
The Economizer setpoint should not be much lower than the Comfort heating setpoint,
otherwise too much cool air would come into the room during the heating sequence.
Above the Outside air temp. min. damper pos. setpoint, the damper is opened
beyond the minimum position if:
– the outside temperature is below the room temperature and
– either the room controller is in Comfort or Precomfort room operating mode
or
one of the special functions "Pre-Cool", "Free Cool", "Night Purge" or "Fan-Only" is
active
The damper is fully closed if:
– the outdoor temperature drops below the frost protection limit (see page 33)
– the safty thermostat for the outdoor temperature is activated (see page 126)
– the special function "Emergency Heat" is active in Economy mode
– the outside air temperature is above the room temperature.
Y [%]
100
min
0
SpFr SpEmc SpC
RXB (KNX) application library
Control sequences
Y
min
TO
SpC
SpEcm Economizer setpoint
SpFr
TO [°C]
FNC Description of functions for FC-10, FC-11, FC-12
Position of damper actuator
Min. damper position
Outside air temperature
Cooling setpoint
= Outdoor temp. min. damper position
Frost protection limit value
CM110385en_05
105/166
28 Feb 2009

Advertisement

   Related Manuals for Siemens Desigo RXB

Comments to this Manuals

Symbols: 0
Latest comments: