Nagas DTH Series User manual

DTH –V9 - 2020
DTH Series
Installation • Outdoor
• Indoor
INSTALLATION AND OPERATION MANUAL
1385, Lionel-Boulet blvd, Varennes,
Quebec, Canada, J3X1P7

1
Installation and operation manual–DTH-V9-2020
This instruction manual should be kept with the unit and be readable.
Warning
FIRE OR EXPLOSION HAZARD
•Failure to follow safety warnings exactly, could result in serious injury, death or property
damage.
•Be sure to read and understand the installation, operation and service instruction in this
manual.
•Improper installation, adjustment, alteration, service or maintenance can cause serious
injury, death or property damages.
•Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.
•WHAT TO DO IF YOU SMELL GAS
oDo not try to light any appliance;
oDo not touch any electrical switch;
oDo not use any phone in your building;
oLeave the building immediately;
oImmediately call your gas supplier from a phone remote from the building. Follow
the gas supplier’s instructions;
oIf you cannot reach your gas supplier, call the fire department;
•Installation and service must be performed by a qualified installer, service agency or the
gas supplier.

2
Installation and operation manual–DTH-V9-2020
Table of contents
Code and regulation .................................................................................................. 3
Specifications............................................................................................................. 4
Gas supply.................................................................................................................. 4
Gas pressure adjustments ......................................................................................... 5
Unit Dimensions ........................................................................................................ 6,7,8
Installation guidelines................................................................................................ 9,10
Electrical control........................................................................................................ 11
Components .............................................................................................................. 11,12,13
Flue vent and combustion air.................................................................................... 14,15,16,17
Start-up instruction ................................................................................................... 18,19
Control sequence....................................................................................................... 20,21,22
Programmable logic controller features & I/O.......................................................... 23,24,25
Display (HMI) features............................................................................................... 26
Run window....................................................................................................... 27
Level 1: Air/Gas relation.................................................................................... 28
Level 1: Alarm history........................................................................................ 29
Level 2: Fan RPM auto tuning........................................................................... 30
Level 2: Signal supervision................................................................................. 31
Level 2: Step timer............................................................................................. 32
PLC alarms.................................................................................................................. 33
Flame safeguard alarms............................................................................................. 34
Flame safeguard troubleshooting ............................................................................. 35
Typical wiring diagram............................................................................................... 36,37
Start / stop recommendations .................................................................................. 38
Unit maintenance ...................................................................................................... 39
Warranty.................................................................................................................... 40
Start-up report........................................................................................................... 41,42
The features, illustrations and description in this document were, to our
knowledge, accurate at the time they were approved for printing. We reserve
the right to change or stop offering some feature as well as stop producing a
given model without prior notice and commitment on our part

3
Installation and operation manual–DTH-V9-2020
Important
This product is intended for installation on positive pressure side of the circulating air blower. This
heating unit is designed for industrial or commercial use only. The installation must comply with the
latest laws and regulation for heating units; CSA B149.1, ANSI Z223.1 / NFPA 54, to the electrical code
C22.1/ NFPA 70 and to local regulations. All inside and outside electrical installation must comply
with the unit’s electrical diagrams.
The electrical, gas and air flow ratings are described on the rating plate applied on the unit. Following
these rating is mandatory for a safe usage of the unit. To learn more, refer to the start-up instruction
and the operating sequence section of this manual.
Clearances to combustible material
A minimum clearance of 1 inch between the unit walls and any combustible material is required on
all side and top. A minimum clearance of 36 inches is required in front of the door to access controls
and 18 inches around the flue vent. Install the unit on a non-combustible floor.
Allocate enough space around the unit for maintenance and around the combustion air intake and
the inlet air hood to prevent harmful accumulation of snow.
Clearances to combustible materials
Position
Inch [mm]
Controls
36 [914]
Top
1 [25]
Back
1 [25]
Flue vent
18 [457]
Floor
Non-combustible
Caution
•Installation, alteration, setting or improper maintenance can cause property damage, injury or
death. Read carefully the installation, start-up and maintenance instruction before installing
or repairing the unit.
•Units installed within a building must have fresh air for combustion in sufficient quantity to
get a good combustion. Refer to CSA B149.1 installation code for Canada and ANSI Z223 for
USA for more information and minimum requirements.
•Gas units must be connected to a flue vent properly sized to ensure proper and safe
operation.
•When required to pipe to outdoor the regulator vent pipes must be terminated with a
downward elbow and a fine mesh screen in order to prevent blockage.
•The above instructions show the recommended installation and usage that we have tested
and get listed. If the installer decides to not follow these instructions, it will be his
responsibility to test safety, functionalities and make it listed by approval agency.
Code and regulation

4
Installation and operation manual–DTH-V9-2020
Electrical supply: 120VAC / 1ph/60Hz –(from 4 to 15 Amp. Refer to name plate for specific value)
Notes: 1. Intended for a temperature rise of 50°F to 120°F (28°C to 67°C)
-1 MBTU: 1000 BTU/ Hr
-CFM: Cubic foot per minute
-Ratings are based on 1000 Btu/ft3for natural gas (2500 Btu/ft3for propane) at sea level. Reduce burner
capacity for altitude over 2000ft by 4% for each 1000ft above sea level.
Important
All gas piping must be performed by a qualified personel following the local codes and CSA B149
installation code for Canada or ANSI Z223.1/NFPA 54 for the United States.
*: With 10’’w.c. minimum inlet pressure.
**: With optional 2’’ NPT gas train for 7’’w.c. inlet pressure. The vent must be piped to outdoor.
***: To be used in ventilated space only. In other case the regulator vent must be piped to outdoor. Use ½’’ NPT tubing.
Note:
•This table should not be used to size the gas supply line.
•If supply gas pressure exceeds 14 inches w.c., a high pressure regulator must be installed at gas piping
inlet. The regulator must be suitable for modulation ratio of 40:1 to properly regulate gas pressure at
low fire.
•The regulator vent must be piped separately towards the outside of the building as stated by CSA B149.1
for Canada and ANSI Z223 for USA and local codes.
DTH
Model
Input capacity
Output capacity
Turndown
ratio
Air flow1
MBTU
kW
MBTU
kW
CFM
I/s
Min.
Max.
Min.
Max.
35
438
128
350
102
15:1
2701
6481
1275
3059
40
500
143
400
117
17:1
3086
7407
1457
3496
50
625
183
500
146
21:1
3858
9259
1821
4370
55
688
201
550
161
17:1
4247
10193
2004
4810
65
813
238
650
190
20:1
5019
12054
2368
5684
75
938
275
750
220
23:1
5790
13896
2733
6558
85
1063
311
850
249
27:1
6562
15748
3097
7432
100
1250
366
1000
293
31:1
7716
18519
3642
8740
125
1563
458
1250
366
26:1
9645
23148
4552
10925
150
1875
549
1500
439
31:1
11574
27778
5462
13110
Dim
Gas train connections (NPT)
Model
35
40
50
55
65
75
85
100
125
150*
150**
Ø Gas
1
1
1
1
1
1
1-1/2
1-1/2
1-1/2
1-1/2
2
Ø Regulator Vent***
N/A: Vent limiter factory installed***
1/2
Ø Vent valve
N/A: Valve proving system included with IRI gas train option.
Specifications
Gas supply

5
Installation and operation manual–DTH-V9-2020
DTH
Model
Natural Gas
Dynamic supply
pressure****
Nominal Manifold
pressure*
Pilot
pressure
Low fire inlet capacity
Minimum
In.w.c [kPa]
Maximum
In.w.c [kPa]
At maximum capacity
In.w.c [kPa]
In.w.c [kPa]
MBH
Kw
35
7”
[1.74]
10”
[2.5]
2.3” [0.57]
3.5” [0.87]
30
8.79
40
2.9” [0.72]
50
4.6” [1.15]
55
3.1” [0.77]
40
11.7
65
2.8” [0.69]
75
2.3” [0.57]
85
2.9” [0.72]
100
3.8” [0.95]
125
2.6” [0.65]
60
17.6
150**
3.9” [0.97]
150***
10”[2.5]
14”[3.5]
4.0” [0.99]
*: The pressure adjustment may vary slightly. See the unit name plate for the exact value.
**: With optional 2’’ NPT gas train.
***: With standard 1-1/2’’ NPT gas train.
****: At maximum capacity (dynamic pressure).
DTH
Model
Propane Gas
Dynamic supply
pressure****
Nominal Manifold
pressure*
Pilot
pressure
Low fire inlet capacity
Minimum
In.w.c [kPa]
Maximum
In.w.c [kPa]
At max. capacity
In.w.c [kPa]
In.w.c [kPa]
Minimum
In.w.c [kPa]
Maximum
In.w.c [kPa]
35
11”
[2.74]
14”
[3.5]
(Consult factory
or rating plate)
2.5” [0.62]
30
8.79
40
50
55
40
11.7
65
75
85
100
125
60
17.6
150
Gas pressure adjustments

6
Installation and operation manual–DTH-V9-2020
DTH - Horizontal discharge
• Left hand control (when facing air stream).
Unit dimensions
WARNING
Improper installation, adjustment, alteration can cause serious injury, death or
property damages.
Note: The controls shown are on the left-hand side of the unit (for a right-hand unit, the drawing is mirrored and
dimensions are identical).
A
AI
AIR
A
AI
AIR

7
Installation and operation manual–DTH-V9-2020
DTH –Vertical discharge
• Left hand control (when facing air stream).
Note: The controls shown are on the left-hand side of the unit (for a right-hand unit, the drawing is mirrored and
dimensions are identical).
A
AIR
A
AIR
A
AIR

8
Installation and operation manual–DTH-V9-2020
Dim
UNIT DIMENSIONS
35
40
50
55
65
75
85
100
125
150
Imperial [in]
A
47
47
47
521/2
521/2
56
58
61
673/4
673/4
B
43
43
43
48 1/4
48 1/4
48 1/4
48 1/4
48 1/4
55
55
C
64 ½
64 ½
64 ½
64 ½
70 ½
70 ½
76
76
78
95 ½
D
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
6 3/4
L
6
6
6
6
6
8
8
10
10
10
M
21 7/8
21 7/8
21 7/8
24 3/8
24 3/8
24 3/8
24 3/8
24 3/8
28 1/2
28 1/2
N
9
9
9
9
9
10
10
11
11
11
P
13 3/8
12 3/8
10 3/8
11 7/8
11 3/8
9 3/8
9 3/8
9 3/8
11
11
Q
17
19
23
25
26
30
30
30
35
35
R
48 1/2
48 1/2
48 1/2
48 1/2
54 1/2
54 1/2
60
60
60
75 1/2
T
21 1/2
21 1/2
21 1/2
21 1/2
21 1/2
21 1/2
21 1/2
21 1/2
26
26
U
10
11 1/2
14 1/2
16
17
19 1/2
20
23
29
28
V
16 7/8
16 1/8
14 5/8
16 3/8
15 7/8
14 5/8
14 3/8
12 7/8
14
14 1/2
W
29 5/8
29 5/8
29 5/8
35
35
36 3/4
37 3/4
39 1/4
46 1/4
46 1/4
AA
56 1/4
58 1/4
62 1/4
70
71
75
75
75
91 3/4
91 3/4
F
19
21
25
27
28
32
32
32
37
37
E
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
8 7/8
S
45
45
45
45
51
51
56 1/2
56 1/2
56 1/2
72
NN
18 1/4
20 1/4
24 1/4
26 1/2
27 1/2
29
27
25
35
35
Dim
Metric [mm]
A
1194
1194
1194
1334
1334
1422
1473
1549
1721
1721
B
1092
1092
1092
1226
1226
1226
1226
1226
1397
1397
C
1638
1638
1638
1638
1791
1791
1930
1930
1981
2426
D
171
171
171
171
171
171
171
171
171
171
L
152
152
152
152
152
203
203
254
254
254
M
556
556
556
619
619
619
619
619
724
724
N
229
229
229
229
229
254
254
279
279
279
P
340
314
264
302
289
238
238
238
279
279
Q
432
483
584
635
660
762
762
762
889
889
R
1232
1232
1232
1232
1384
1384
1524
1524
1524
1918
T
546
546
546
546
546
546
546
546
660
660
U
254
292
368
406
432
495
508
584
737
711
V
429
410
371
416
403
371
365
327
356
368
W
752
752
752
889
889
933
959
997
1175
1175
AA
1429
1480
1581
1778
1803
1905
1905
1905
2330
2330
F
483
533
635
686
711
813
813
813
940
940
E
225
225
225
225
225
225
225
225
225
225
S
1143
1143
1143
1143
1295
1295
1435
1435
1435
1829
NN
464
514
616
673
699
737
686
635
889
889

9
Installation and operation manual–DTH-V9-2020
•Install the unit on the positive side of the air-circulating blower (supply side).
•The air intake must be located in order to avoid snow, rain, flammable, toxic gases and other
harmful substances from entering the heater.
•In operation mode, the system design must provide enough air to the heat exchanger to ensure a
temperature rise between 50°F (28°C) and 120°F (67°C) and maintain an average supply
temperature of 130°F (54°C) maximum. Note that the temperature high limit protection is
factory set at 160°F (71°C).
•The inlet ducting must have the same cross-sectional area as the inlet connection. Both inlet and
outlet ducts must have a removable access panel. These panels shall be sized to permit
inspection of the heat exchanger at start-up on routine inspection.
•If fire dampers are used, they must be equipped with switches connected to the safety control
circuit in order to interrupt the heater if there is a fire or high temperature in the ventilation
duct. The electric actuators must be adjusted in order to close the safety loop on the flame
safeguard only when the dampers are fully open.
•Depending on the model, the flue vent connection diameter ranges from 6 to 10 inch. The DTH
models are designed to operate effectively and safely with a positive stack (category III) type
sealed single wall or double wall flue vent listed for this application, whether vertical or
horizontal arrangement or a combination of both. The minimum diameter of all sections must be
identical to the unit’s connection diameter. Refer to the exhaust system sections of this manual.
•If no control cabinet is supplied by Nagas with the unit, the installer must be made one for
component protection and must include aeration openings at least equal of two 2 inches holes.
See gas installations code for more requirements.
IMPORTANT NOTICE
•In order to minimize the risk of freezing pipes inside the building, the installer must equip
the system with a low temperature sensor that will interrupt operation, stop the fan and
close the dampers in the event that low temperature (lower than 40oF) are detected
downstream of the heater.
•In certain conditions these units can produce condensate. This corrosive liquid must be
treated and drain correctly with provision to prevent freezing.
•It is necessary to mechanically attach the unit to the roof base or other support structure
with screws or other suitable fasteners to prevent wind or earthquake damage.
Installation guidelines