Mestek 108A User manual

HIM-16
J30-05404
INSTALLATION INSTRUCTIONS & PARTS LIST
HORIZONTAL STEAM AND HOT WATER UNIT HEATERS
Model No. Serial No.
ATTENTION: READTHIS MANUAL AND ALL LABELS ATTACHEDTOTHE UNIT CAREFULLY BEFORE
ATTEMPTINGTO INSTALL,OPERATE OR SERVICETHESE UNITS! CHECK UNIT DATA PLATE FORTYPE
OFGASAND ELECTRICAL SPECIFICATIONSAND MAKE CERTAINTHATTHESEAGREEWITHTHOSEAT
POINT OF INSTALLATION. RECORD THE UNIT MODEL AND SERIAL No.(s) IN THE SPACE PROVIDED.
RETAIN FOR FUTURE REFERENCE.
INSTALLER’S RESPONSIBILITY
Installer Please Note: This equipment has been tested and
inspected. It has been shipped free from defects from our
factory. However, during shipment and installation, problems
such as loose wires, leaks or loose fasteners may occur. It is
the installer’s responsibility to inspect and correct any
problems that may be found.
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
injury or death. Read the installation, operating and
maintenance instructions thoroughly before installing or
servicing this equipment.
RECEIVING INSTRUCTIONS
Inspect shipment immediately when received to determine if
any damage has occurred to the unit during shipment. After
the unit has been uncrated, check for any visible damage to
the unit.Turn fan by hand to determine if damage has occurred.
If any damage is found, the consignee should sign the bill of
lading indicating such damage and immediately file claim for
damage with the transportation company.
08/12
260 NORTH ELM ST.
WESTFIELD, MA 01085

2
TABLE OF CONTENTS
GENERAL SAFETY INFORMATION ..........................3
SPECIFICATIONS
Dimensional Data ..................................................4
Steam Performance Data .......................................5
Steam Calculations & Correction Factors...............6
Hot Water Performance Data .................................7
Hot Water Calculations & Correction Factors ........8
Technical Data .......................................................9
Motor Data ...........................................................10
LOCATION ................................................................11
INSTALLATION
Unit Mounting .......................................................12
Piping...............................................................12-16
The following terms are used throughout this manual, in addition to ETL requirements, to bring attention to the
presence of potential hazards or to important information concerning the product:
Horizontal hydronic unit heaters are available in both
serpentine and header type units. Serpentine units offer
outputs from 8,030 to 35,900 BTU’s (2.4 to 10.5 kW) and
are ideal for hot water (only) installations with limited
clearances. Header type horizontal units range from
18,000 to 360,000 (5.3 to 105.5 kW) and can operate
with either hot water or steam. Both units are furnished
Figure 1
Serpentine
Type
Indicates an imminently hazardous
situation which,if not avoided, will result in death,
serious injury or substantial property damage.
Indicatesan imminently hazardous
situation which, if not avoided, could result in
death, serious injury or substantial property
damage.
Indicatesanimminentlyhazardous
situationwhich,ifnotavoided,mayresultinminor
injury or property damage.
NOTICE: Used to notify of special instructions on
installation, operation or maintenance which are
important to equipment but not related to personal
injury hazards.
ELECTRICAL CONNECTIONS ................................17
Operation .............................................................17
Thermostat Wiring and Location ..........................17
WIRING INSTALLATION ..........................................18
OPTIONS .................................................................19
MAINTENANCE .......................................................20
REPLACEMENT PARTS ..........................................21
TROUBLESHOOTING GUIDE..................................22
WARRANTY..............................................................23
INSPECTION SHEET................................................24
NOTICE: It is the owner’s responsibility to provide any scaffolding or other apparatus required to perform
emergency service or annual/periodic maintenance to this equipment.
Figure 2
Header
Type
with totally enclosed motors, with explosion proof motors
as optional on header types. The designs are certified
by ETL. Do not alter these units in any way and do
not attach any ductwork to the units. If you have
any questions after reading this manual, contact the
manufacturer.
DESCRIPTION

3
Failure to comply with the general
safety information may result in extensive
propertydamage,severe personalinjury ordeath.
Do not alter the unit heater in any
wayor damage to the unit and/or severepersonal
injury or death may occur!
Disconnect all power supplies
before installing or servicing the heater. If the
power disconnect is out of sight, lock it in the
open position and tag it to prevent unexpected
application of power.Failure to do so could result
in fatal electric shock, or severe personal injury.
Insure that all power sources
conform to the requirements of the unit heater
or damage to the unit will result!
Follow installation instructions CAREFULLY to avoid
creating unsafe conditions. All external wiring must
conform to applicable current local codes, and to the
latest edition of the National Electric Code ANSI/NFPA
No. 70. In Canada, all external wiring must conform
to the Canadian Electric Code, Part 1 CSA Standard
C22.1 All wiring should be done and checked by a
qualified electrician using copper wire only. All steam
and hot water connections should be made and leak-
tested by a suitably qualified individual, per instructions
in this manual.Also follow procedures listed on the “Unit
Equipment Start-Up Sheet” located in this manual.
Make certain that the power source conforms to the
electrical requirements of the heater.
Do not depend upon a thermostat
or other switch as sole means of disconnecting
power when installing or servicing heater.Always
disconnect power at main circuit breaker as
described above. Failure to do so could result in
fatal electric shock.
Special attention must be given to any grounding
information pertaining to this heater. To prevent the
risk of electrocution, the heater must be securely and
adequately grounded. This should be accomplished by
connecting a grounded conductor between the service
panel and the heater. To ensure a proper ground,
the grounding means must be tested by a qualified
electrician.
GENERAL SAFETY INFORMATION
Do not insert fingers or foreign objects into the heater
or its air moving device. Do not block or tamper with the
heater in any manner while in operation or just after it
has been turned off, as some parts may be hot enough
to cause injury.
To meet ETL and OSHA requirements, units
mounted below 8 feet (2.4m) from the floor must be
equipped with an OSHA fan guard.
It is good practice to have a shutoff switch on the
electrical power lines controlling the heater.Whenever a
unit is serviced, shut power off to the unit.
Since these units are installed in most instances higher
than 8 feet (2.4m), proper type of ladders or scaffolding
should be used, as set up by OSHA requirements (see
Notice on page 2).
In industrial plants, professional maintenance crews
should service this equipment.
All Horizontal Unit Heaters are shipped fully assembled
and may be used for steam or hot water applications.
Coils are factory tested at 250 psig (1723.5 kg).
Each unit is packaged individually and marked for proper
identification. Use normal care in handling and during
installation to prevent damage to the coils fins, fan and
casing.
Unless otherwise specified, the following conversions
may be used for calculating SI unit measurements:
1foot= 0.305m
1inch =25.4 mm
1psig =6.894 kPa
1pound =0.453 kg
1gallon =3.785 L
1inch watercolumn= 0.249kPa
meter/second= FPM÷ 196.8
liter/second= CFMx 0.472
1000Btu perhour =0.293 kW
1000Btu/Cu.Ft.=37.5 MJ/m3
1cubic foot =0.028 m3

4
145⁄8
(371)
145⁄8
(371)
171⁄8
(435)
171⁄8
(435)
183⁄8
(467)
207⁄8
(530)
195⁄8
(498)
207⁄8
(530)
233⁄8
(594)
233⁄8
(594)
245⁄8
(625)
277⁄8
(708)
277⁄8
(708)
333⁄8
(848)
12¼
(311)
12¼
(311)
14¾
(375)
14¾
(375)
16
(406)
18½
(470)
17¼
(438)
18½
(470)
21
(533)
21
(533)
22¼
(565)
25½
(648)
25½
(648)
31
(787)
4
5
6
6
7
8
8
8
9
9
9
10
10
13
18
24
36
48
60
72
84
96
108
120
132
144
156
180
204
240
280
300
360
75⁄16
(186)
75⁄16
(186)
89⁄16
(217)
89⁄16
(217)
93⁄16
(233)
107⁄16
(265)
913⁄16
(249)
107⁄16
(265)
1111⁄16
(297)
1111⁄16
(297)
125⁄16
(313)
1315⁄16
(354)
1315⁄16
(354)
1611⁄16
(424)
15
(381)
18
(457)
20½
(521)
20½
(521)
21¾
(552)
24¼
(616)
24
(610)
25¼
(641)
27¾
(705)
27¾
(705)
29
(737)
30¼
(768)
30¼
(768)
37¾
(959)
7½
(191)
9
(229)
10¼
(260)
10¼
(260)
107⁄8
(276)
121⁄8
(308)
12
(305)
125⁄8
(321)
137⁄8
(352)
137⁄8
(352)
14½
(368)
151⁄8
(384)
151⁄8
(384)
187⁄8
(479)
61⁄8
(156)
61⁄8
(156)
57⁄8
(149)
57⁄8
(149)
6
(152)
61⁄8
(156)
65⁄16
(160)
65⁄16
(160)
65⁄16
(160)
65⁄16
(160)
63⁄8
(162)
81⁄8
(206)
81⁄8
(206)
9
(229)
215⁄16
(75)
215⁄16
(75)
215⁄16
(75)
215⁄16
(75)
215⁄16
(75)
215⁄16
(75)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
33⁄16
(81)
3¼
(83)
3¼
(83)
511⁄16
(144)
51⁄16
(129)
51⁄16
(129)
511⁄16
(144)
7½
(191)
611⁄16
(170)
75⁄8
(194)
77⁄16
(194)
77⁄16
(194)
57⁄8
(149)
95⁄8
(244)
95⁄8
(244)
93⁄8
(238)
93⁄8
(238)
117⁄16
(291)
1015⁄16
(278)
111⁄16
(281)
1113⁄16
(300)
1313⁄16
(351)
13
(330)
14
(356)
13¾
(349)
13¾
(349)
14
(356)
17¾
(451)
185⁄8
(473)
9½
(241)
12½
(318)
15
(381)
15
(381)
16¼
(413)
18¾
(476)
17½
(445)
18¾
(476)
21¼
(540)
21¼
(540)
22½
(572)
23¾
(603)
23¾
(603)
31¼
(794)
1¼
(32)
1¼
(32)
1¼
(32)
1¼
(32)
1¼
(32)
1¼
(32)
1½
(38)
1½
(38)
1½
(38)
1½
(38)
1½
(38)
2
(51)
2
(51)
2
(51)
2¼
(57)
2¼
(57)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
1¾
(44)
127⁄8
(327)
127⁄8
(327)
153⁄8
(391)
153⁄8
(391)
165⁄8
(422)
191⁄8
(486)
177⁄8
(454)
191⁄8
(486)
215⁄8
(549)
215⁄8
(549)
227⁄8
(581)
261⁄8
(664)
261⁄8
(664)
315⁄8
(803)
9
(229)
10
(254)
12
(305)
12
(305)
14
(356)
14
(356)
16
(406)
18
(457)
18
(457)
18
(457)
18
(457)
20
(508)
20
(508)
24
(610)
26
(11.8)
30
(13.6)
41
(18.6)
41
(18.6)
44
(19.9)
47
(21.3)
49
(22.2)
59
(26.7)
74
(33.5)
74
(33.5)
90
(40.8)
143
(65)
154
(70)
203
(92)
22 (10.0)
24 (10.9)
25 (11.3)
31 (14.0)
APPROX.
SHIPWT.
lbs. (kg)
DIMENSIONAL DATA
Figure 3 – SerpentineType
Models 108A, 118A, 125A, 136A
Table 2 – Figure 4 Header Models NOM. FAN
DIAM.
inches (mm)
NO.
OF
LOUVERS
MODEL
* Applies to standard motor with standard fan guard. When optional motors or OSHA fan guards are requested, dimensions will vary according to
the substitutions made.
NOTES: 1. OSHA guard standard on all serpentine models and header models 18 thru 48 supplied with 1 phase motors (dimensions shown in tables).
2. Standard motor and standard guard shown.
3. All 3 phase and explosion proof motors are shelf mounted.
A B C D E F G* H* J K L M N
inches inches inches inches inches inches inches inches inches inches inches inches inches
(mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)
Figure 4 – HeaderType
Models 18 thru 360
H
inches (mm) B inches (mm)
APPROX.
SHIPWT.
lbs. (kg)
NOM.
FAN DIAM.
inches (mm)
NO.
OF
LOUVERS
C
inches (mm)
108A
118A
125A
136A
W
inches (mm)
MODEL
5
5
5
6
Table 1 – Figure 3 Serpentine Models
NOTE: Motors are totally enclosed, thermally protected, sleeve bear-
ing, with 2"(h) x 4"(w) conduit connection boxes.3/8-16 nutserts are
attached to enclosure for balanced hanging.
A
inches (mm)
16 (406)
16 (406)
16 (406)
18½ (470)
18 (457)
18 (457)
18 (457)
20½ (521)
167⁄32 (412)
167⁄32 (412)
167⁄32 (412)
1822⁄32 (475)
11¼ (286)
11¼ (286)
11¼ (286)
13¾ (349)
4¼ (108)
4¼ (108)
4¼ (108)
511⁄16 (144)
9 (229)
10 (254)
10 (254)
12 (305)

5
18
24
36
48
60
72
84
96
108
120
132
144
156
180
204
240
280
300
360
395
(2.007)
330
(1.676)
450
(2.286)
380
(1.930)
550
(2.794)
480
(2.438)
550
(2.794)
460
(2.337)
650
(3.302)
510
(2.591)
800
(4.064)
700
(3.556)
900
(4.572)
750
(3.810)
930
(4.724)
800
(4.064)
1000
(5.080)
900
(4.572)
900
(4.572)
950
(4.826)
1000
(5.080)
1150
(5.842)
800
(4.064)
1000
(5.080)
900
(4.572)
980
(4.978)
700
(3.556)
1000
(5.080)
395
(.186)
330
(.156)
450
(.212)
380
(.179)
550
(.260)
480
(.227)
750
(.354)
630
(.297)
900
(.425)
700
(.330)
1100
(.519)
950
(.448)
1400
(.661)
1100
(.519)
1400
(.661)
1100
(.519)
1800
(.850)
1500
(.708)
1900
(.897)
2000
(.944)
2200
(1.038)
2600
(1.227)
2200
(1.038)
2900
(1.369)
3500
(1.652)
4200
(1.982)
5000
(2.360)
5500
(2.596)
1550
1350
1550
1350
1550
1350
1000
900
1000
900
1000
900
1000
900
1000
900
1000
900
1140
1140
1140
1140
1140
1140
1140
1100
1100
1100
16 Watts
16 Watts
25 Watts
1/20
(.037)
1/20
(.037)
1/20
(.037)
1/12
(.062)
1/12
(.062)
1/12
(.062)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/2
(.373)
1/2
(.373)
1/2
(.373)
102
(39)
105
(41)
109
(43)
112
(44)
119
(48)
120
(49)
119
(48)
123
(51)
121
(49)
131
(55)
120
(49)
123
(51)
115
(46)
123
(51)
123
(51)
132
(56)
115
(46)
120
(49)
118
(48)
121
(49)
120
(49)
115
(46)
135
(57)
124
(51)
123
(51)
121
(49)
117
(47)
120
(49)
75
(7.0)
68
(6.3)
100
(9.3)
90
(8.4)
150
(13.9)
135
(12.5)
200
(18.6)
180
(16.7)
250
(23.2)
225
(20.9)
300
(27.9)
270
(25.1)
350
(32.5)
315
(29.3)
400
(37.2)
360
(33.4)
450
(41.8)
405
(37.6)
500
(46.5)
550
(51.1)
600
(55.7)
650
(60.4)
770
(71.5)
850
(79.0)
1000
(92.9)
1100
(102.2)
1250
(116.1)
1500
(139.4)
18.0
(8.2)
16.2
(7.3)
24.5
(11.1)
22.0
(10.0)
37.0
(16.8)
33.0
(14.9)
49.0
(22.2)
44.0
(19.9)
61.0
(27.6)
55.0
(24.9)
73.0
(33.1)
66.0
(29.9)
85.0
(38.5)
76.0
(34.4)
97.0
(43.9)
88.0
(39.9)
110.0
(49.8)
98.0
(44.4)
122.0
(55.3)
134.0
(60.7)
146.0
(66.1)
160.0
(72.5)
190.0
(86.1)
208.0
(94.2)
244.0
(110.5)
280.0
(126.8)
310.0
(140.4)
366.0
(165.8)
18,000
(5.3)
16,200
(4.7)
24,000
(7.0)
21,600
(6.3)
36,000
(10.5)
32,400
(9.5)
48,000
(14.1)
43,200
(12.7)
60,000
(17.6)
54,000
(15.8)
72,000
(21.1)
64,800
(19.0)
84,000
(24.6)
75,600
(22.2)
96,000
(28.1)
86,400
(25.3)
108,000
(31.6)
97,200
(28.5)
120,000
(35.2)
132,000
(38.7)
144,000
(42.2)
156,000
(45.7)
180,000
(52.7)
204,000
(59.8)
240,000
(70.3)
280,000
(82.0)
300,000
(87.9)
360,000
(105.5)
9
(228.6)
9
(228.6)
10
(254.0)
10
(254.0)
10
(254.0)
10
(254.0)
12
(304.8)
12
(304.8)
12
(304.8)
12
(304.8)
14
(355.6)
14
(355.6)
14
(355.6)
14
(355.6)
16
(406.4)
16
(406.4)
16
(406.4)
16
(406.4)
18
(457.2)
18
(457.2)
18
(457.2)
18
(457.2)
18
(457.2)
18
(457.2)
20
(508.0)
20
(508.0)
24
(609.6)
24
(609.6)
0.80
0.80
1.2
1.4
1.4
1.4
2.2
2.2
2.2
4.5
4.5
4.5
4.5
4.5
4.5
4.5
5.4
5.4
5.4
STEAM PERFORMANCE DATA
Table 3 - HeaderType Models only
Output
BTU/
HR*
(kW)
Unit
Size
Final Air
Deg.°F
(Deg. °C)
Motor
HP
(kW) RPM
E.D.R.
Sq. Ft.
(sq. m)
Cond.
lbs./hr.
(kg/hr)
Nom.
Amps
@
115VAC†
Nom. Fan
Diam.
Inches
(mm)
Outlet
FPM
(m/s)
Nominal
CFM
(m3/s)
Performance based on 2# steam pressure (13.8 kpa) at heater with air entering @ 60°F (16°C).
For Sound Ratings See Pages 7 & 9.
Use conversionTable on page 3 for all metric conversions.
*For the lower output, an optional Speed Controller must be ordered.
†Stated AMP is full load for the standard motors. AMP draw varies by motor manufacturer ± 0.2 AMPS. Please see your unit’s motor
data plate for exact (FLA) Full Load Amp rating. Additional motor data is shown on page 10.

6
EXAMPLE: –
UNITSIZE: _________24
SteamPressure___10PSI
EnteringAirTemp. __ 40°F
I. CAPACITY
A.For2lbs.steam,60°enteringair ReadoutputdirectlyfromTable3,24,000BTU/HR.
(Ref.,Std.24).
B.Forhighersteampressures MultiplyoutputfromTable3byappropriatecorrection
and/orE.A.T.’saboveorbelow60°F factorfromTable4(below). 24,000x1.29=30,960BTU/HR.
II. FINAL AIRTEMPERATURE
A.For2lbs.steam,60°enteringair ReadtemperaturedirectlyfromTable3,109°F.
(Ref.,Std.24).
B.ForcapacitiescalculatedinI.B.(above) OutputfromI.B. +E.A.T.=FinalAirTemp. 30,960 +40=103.4°F.
1.085xCFMfromTable3 1.085x450
III. FINAL AIRVOLUME Nom.CFM Final
A.For2lbs.steam,60°enteringair 460+FinalAirTempfromTable3 xfrom = Air 460+109 x450=483CFM
530 Table3 Volume 530
Nom.CFM Final
B.Forfinalairtemperaturescalculated 460+FinalAirTempfromII.B. xfrom = Air 460+103.4 x450=478CFM
InII.B.(above) 530 Table3 Volume 530
IV. CONDENSATE PER HOUR Readlbs.perhourfromTable3,24.5LBS./HR.
A.For2lbs.steam,60°enteringair (Ref.,Std.24).
B.ForcapacitiescalculatedinI.B.(above) OutputfromI.B. =lbs.perhourofcondensate 30,960 =32.5LBS./HR.
LatentHeatFromTable5 953
30 -(1)
40 (4)
50 (10)
60 (16)
70 (21)
80 (27)
90 (32)
100 (38)
STEAM PRESSURE (SATURATED) — LBS. PER SQ. IN. (kPa)
STEAM PRESSURE IN PSIG (kPa)
15
(103.4)
249.8
(121.0)
946
(2200)
2
(13.8)
218.5
(103.6)
966
(2247)
10
(68.9)
239.4
(115.2)
953
(2217)
Steam Pressure
psi (kPa)
Steam Temperature
Deg. F (Deg. C)
Latent Heat of Steam
Btu/lbm (KJ/Kg)
0
(0)
212
(100)
970
(2256)
15
(103.4)
1.44
1.34
1.28
1.19
1.12
1.04
0.97
0.89
5
(34.5)
1.29
1.21
1.13
1.05
0.97
0.90
0.83
0.76
2
(13.8)
1.24
1.16
1.08
1.00
0.93
0.85
0.78
0.71
ENTERING AIR
TEMPERATURE
Deg. F (Deg. C)
10
(68.9)
1.38
1.29
1.21
1.13
1.06
0.98
0.91
0.84
TABLE 4 — STEAM CORRECTION FACTORS BASED ON
2 PSI (13.8 kPa) STEAM AND 60 Deg. F (16 Deg. C) E.A.T.
0
(0)
1.19
1.11
1.03
0.96
0.88
0.81
0.74
0.67
TABLE 5 — PROPERTIES OF SATURATED STEAM
STEAM CALCULATIONS AND CORRECTION FACTORS
5
(34.5)
227.1
(108.4)
961
(2235)
20
(137.9)
1.50
1.42
1.33
1.25
1.17
1.10
1.02
0.95
30
(206.8)
1.60
1.51
1.43
1.35
1.27
1.19
1.12
1.04
40
(275.8)
1.68
1.60
1.51
1.43
1.35
1.27
1.19
1.12
50
(344.7)
1.70
1.66
1.58
1.50
1.42
1.34
1.26
1.19
75
(517.1)
1.90
1.81
1.72
1.64
1.55
1.47
1.39
1.32
30
(206.8)
274.0
(134.4)
929
(2161)
50
(344.7)
297.7
(147.6)
912
(2121)
75
(517.1)
319.9
(159.9)
891
(2072)
40
(275.8)
286.7
(141.5)
920
(2140)
20
(137.9)
258.8
(126.0)
940
(2186)
100
(689.4)
2.02
1.93
1.84
1.75
1.66
1.58
1.50
1.42
125
(861.8)
2.11
2.02
1.93
1.84
1.76
1.68
1.59
1.51
150
(1,034.1)
2.20
2.11
2.02
1.93
1.84
1.76
1.67
1.59
125
(891.8)
352.9
(178.3)
868
(2019)
150
(1,034.1)
365.9
(185.5)
857
(1993)
100
(689.4)
337.9
(169.9)
881
(2049)

7
II
I
II
I
II
I
II
I
II
I
II
I
II
I
II
I
II
I
II
I
III
II
III
II
III
II
III
IV
IV
IV
III
IV
IV
IV
IV
IV
250
(1.270)
215
(1.092)
500
(2.540)
420
(2.134)
590
(2.997)
450
(2.286)
550
(2.794)
480
(2.438)
395
(2.007)
350
(1.778)
450
(2.286)
380
(1.930)
550
(2.794)
480
(2.438)
550
(2.794)
460
(2.337)
650
(3.302)
510
(2.591)
800
(4.064)
700
(3.556)
900
(4.572)
750
(3.810)
930
(4.724)
800
(4.064)
1000
(5.080)
900
(4.572)
900
(4.572)
950
(4.826)
1000
(5.080)
1150
(5.842)
800
(4.064)
1000
(5.080)
900
(4.572)
980
(4.978)
700
(3.556)
1000
(5.080)
91
(33)
90
(32)
94
(34)
96
(36)
102
(39)
106
(41)
99
(37)
100
(38)
95
(35)
99
(37)
96
(36)
98
(37)
103
(39)
103
(39)
103
(39)
111
(44)
105
(41)
112
(44)
104
(40)
106
(41)
100
(38)
106
(41)
106
(41)
113
(45)
100
(38)
103
(39)
102
(39)
104
(40)
104
(40)
100
(38)
110
(43)
107
(42)
106
(41)
106
(41)
102
(39)
103
(39)
108A
118A
125A
136A
18
24
36
48
60
72
84
96
108
120
132
144
156
180
204
240
280
300
360
HOT WATER PERFORMANCE DATA
Table 6 - Serpentine and HeaderType Models
Output
BTU/
HR*
(kW)
Unit
Size
Final
Air
Deg. °F
(Deg. °C)
Motor
HP
(kW)
Prssr.
Drop
FT./H2O
(m/water)
Nom.
Amps
@
115VAC† Sound
Rating
Outlet
FPM
(m/s)
Nominal
CFM
(m3/s)RPM
Performance based on 200°F (93°C) EWT, 60°F (16°C) E.A.T., 20°F (11°C)TD.
For Fan Diameter See Page 4.
Use conversionTable on page 3 for all metric conversions.
*For the lower output, an optional Speed Controller must be ordered.
†Stated AMP is full load for standard motors. AMP draw varies by motor manufacturer ± 0.2 AMPS. Please see your unit’s motor
data plate for exact (FLA) Full Load Amp rating. Additional motor data is shown on page 10.
8,030
(2.4)
6,800
(2.0)
18,400
(5.4)
15,650
(4.6)
24,800
(7.3)
21,230
(6.2)
35,900
(10.5)
32,300
(9.5)
13,050
(3.8)
11,725
(3.4)
17,400
(5.1)
15,600
(4.6)
26,100
(7.6)
23,500
(6.9)
34,800
(10.2)
31,300
(9.2)
43,600
(12.8)
39,200
(11.5)
52,300
(15.3)
47,000
(13.8)
61,000
(17.9)
54,900
(16.1)
69,700
(20.4)
62,700
(18.4)
78,400
(23.0)
70,500
(20.7)
87,100
(25.5)
95,800
(28.1)
104,000
(30.5)
113,000
(33.1)
118,000
(34.6)
148,000
(43.4)
174,000
(51.0)
209,100
(61.3)
230,000
(67.4)
261,300
(76.6)
0.8
(.050)
1.9
(.120)
2.5
(.158)
3.6
(.227)
1.3
(.082)
1.8
(.114)
2.7
(.170)
3.5
(.221)
4.4
(.278)
5.3
(.334)
6.1
(.385)
7.0
(.442)
7.9
(.498)
8.8
(.555)
9.6
(.606)
10.4
(.656)
11.3
(.713)
11.8
(.744)
14.9
(.940)
17.4
(1.098)
21.0
(1.325)
23.0
(1.451)
26.2
(1.653)
0.80
(.244)
2.20
(.671)
2.20
(.671)
3.00
(.914)
0.005
(.002)
0.014
(.004)
0.09
(.027)
0.12
(.037)
0.17
(.052)
0.23
(.070)
0.24
(.073)
0.29
(.088)
0.36
(.110)
0.39
(.119)
0.41
(.125)
0.43
(.131)
0.53
(.162)
0.6
(.183)
0.79
(.241)
1.06
(.323)
1.33
(.405)
2.1
(.640)
2.1
(.640)
16 Watts
16 Watts
25 Watts
1/20
(.037)
16 Watts
16 Watts
25 Watts
1/20
(.037)
1/20
(.037)
1/20
(.037)
1/12
(.062)
1/12
(.062)
1/12
(.062)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/3
(.249)
1/2
(.373)
1/2
(.373)
1/2
(.373)
1550
1350
1550
1350
1550
1350
1000
900
1550
1350
1550
1350
1550
1350
1000
900
1000
900
1000
900
1000
900
1000
900
1000
900
1140
1140
1140
1140
1140
1140
1140
1100
1100
1100
245
(.116)
210
(.099)
500
(.236)
420
(.198)
580
(.274)
460
(.217)
850
(.401)
750
(.354)
395
(.186)
350
(.165)
450
(.212)
380
(.179)
550
(.260)
480
(.227)
750
(.354)
630
(.297)
900
(.425)
700
(.330)
1100
(.519)
950
(.448)
1400
(.661)
1100
(.519)
1400
(.661)
1100
(.519)
1800
(.850)
1500
(.708)
1900
(.897)
2000
(.944)
2200
(1.038)
2600
(1.227)
2200
(1.038)
2900
(1.369)
3500
(1.652)
4200
(1.982)
5000
(2.360)
5500
(2.596)
0.80
0.80
1.2
1.4
0.80
0.80
1.2
1.4
1.4
1.4
2.2
2.2
2.2
4.5
4.5
4.5
4.5
4.5
4.5
4.5
5.4
5.4
5.4
Flow
Rate
GPM
(L/s)

8
To obtain output for other Water Temperature Drops,
multiply basic output rating by applicable Factor.
To obtain flow for otherWaterTemperature Drops,
multiply basic rate rating by applicable Factor.*
To obtain Pressure Loss Feet (Meters) of Water
for other temperature Drops, multiply Basic loss
at 20°F (11°C) drop by Factor.
MODEL No.
MINIMUM
GPM (L/s)
MODEL No.
MINIMUM
GPM (L/s)
EXAMPLE: –
UNITSIZE:_______________________24
EnteringWaterTemp. ____________ 160°F
EnteringAirTemp. _______________ 40°F
WaterTemperatureDrop __________ 10°F
I. CAPACITY@20°TD:
A.For200°EWT,60°EAT ReadoutputdirectlyfromTable6,
17,400BTU/HR(Ref.,Std.24).
B.ForEWTand/orEATabove MultiplyoutputfromTable6
orbelowStandard byfactorfromTable7(below). 17,400x.878=15,277 BTU/HR.
II. CAPACITYATOTHERTD’s MultiplyoutputobtainedinIA.orIB. IA-17,400x1.15=20,010BTU/HR.
A.ForTD’sfrom5to60°F (above)byappropriatefactorfromTable8 –OR–
(below) IB-15,277x1.15=17,569BTU/HR.
III. GPMATOTHERTD’s MultiplyGPMofunitfor20°TD,fromTable6
1.8x2.30=4.14GPM(Appliesonlytounitswith
A.ForTD’sfrom5to60°F byappropriatefactorfromTable8(below). Std.200°EWT,60°EAT.)Forallotherscalculate
BTUusingformula–GPM=
500xTD
IV. CAPACITY AT OTHER RATES MultiplyoutputfromTable6byfactor
OFWATERFLOW fromTable10(below).
V. PRESSURELOSSATOTHER TD’s MultiplyP.D.ofunitfor20°TD,fromTable6
A.ForTD’sfrom5to60°F byappropriatefactorfromTable8(below). .014x5.00=.07Ft.H2O
100°
(38)
0.518
0.439
0.361
0.286
0.212
0.140
0.069
0.000
120°
(49)
0.666
0.585
0.506
0.429
0.353
0.279
0.207
0.137
140°
(60)
0.814
0.731
0.651
0.571
0.494
0.419
0.345
0.273
160°
(71)
0.963
0.878
0.796
0.715
0.636
0.558
0.483
0.409
240°
(116)
1.555
1.464
1.375
1.286
1.201
1.117
1.035
0.955
260°
(127)
1.702
1.609
1.518
1.429
1.342
1.257
1.173
1.094
TABLE 7 — HOT WATER CONVERSION FACTORS BASED ON 200° (93°C) ENTERING WATER,
60° (16°C) ENTERING AIR AND 20° (11°C) TEMPERATURE DROP
TABLE 8 — HOT WATER OUTPUT, FLOW RATE AND PRESSURE LOSS FACTORS BASED ON STANDARD
CONDITIONS OF 200°F (93°C) ENTERING WATER, 60°F (16°C) ENTERING AIR & 20°F (11°C) WATER DROP
*TABLE 9 — MINIMUM WATER FLOW
*TABLE 10 — HEATING CAPACITY FACTORS FOR VARIOUS RATES OF WATER FLOW
ENTERING AIR
TEMPERATURE
°F (°C)
30 -(1)
40 (4)
50 (10)
60 (16)
70 (21)
80 (27)
90 (32)
100 (38)
ENTERING WATER TEMPERATURE — °F (°C)
180°
(82)
1.120
1.025
0.941
0.857
0.777
0.698
0.621
0.546
200°
(93)
1.268
1.172
1.085
1.000
0.918
0.837
0.759
0.682
220°
(104)
1.408
1.317
1.231
1.143
1.060
0.977
0.897
0.818
280°
(138)
1.850
1.755
1.663
1.571
1.483
1.397
1.311
1.230
300°
(149)
1.997
1.908
1.824
1.717
1.630
1.545
1.462
1.371
5
(3)
1.25
5.00
10.00
25
(14)
.94
.74
.60
30
(17)
.90
.59
.40
20
(11)
1.00
1.00
1.00
60
(33)
.72
.24
.07
40
(22)
.83
.40
.20
50
(28)
.76
.30
.13
TEMPERATURE DROP °F (°C)
USE FACTORS FROM THIS TABLE TO OBTAIN
APPROXIMATE RESULTS
96
3.350
(.211)
132
4.09
(.258)
360
6.08
(.384)
300
6.08
(.384)
72
1.620
(.102)
84
1.860
(.117)
125A
0.125
(.008)
60
1.490
(.094)
280
4.59
(.290)
48
1.490
(.094)
240
4.59
(.290)
204
4.34
(.274)
36
1.240
(.078)
180
4.34
(.274)
24
1.240
(.078)
156
4.09
(.258)
18
0.750
(.047)
144
4.09
(.258)
136A
0.125
(.008)
118A
0.125
(.008)
120
3.60
(.227)
108A
0.125
(.008)
108
3.35
(.211)
175%
1.10
25%
.80 75% .96 125% 1.04 150% 1.07
50%
.89
% of Rated Water Flow
Heating Capacity Factor 100% 1.00
10
(6)
1.15
2.30
5.00
15
(8)
1.08
1.44
2.00
HOT WATER CALCULATIONS AND CORRECTION FACTORS

9
CORRECTIONSWHEN USING GLYCOL SOLUTION IN SYSTEM
TECHNICAL DATA
SOUND RATING
I
II
III
IV
V
III - VII*
CATEGORY OF AREA
Apartment, assembly hall, classrooms
churches, courtrooms, executive offices,
hospitals, libraries, museums, theatres.
Dining rooms, general offices, recreation
areas, small retail stores.
Restaurants, banks, cafeterias, depart-
ment stores, public buildings, service
stations.
Gymnasiums, health clubs,
laundromats, supermarkets.
Garages, small machine shops, light
manufacturing.
Factories, foundries, steel mills.
*Depending on specific use in these
facilities, size of operation, etc.
TECHNICAL DATA
Propylene
Glycol
1. Heat transfer 20% solution .97*
@180°F (82°C) with
no increase in flow rate 50% solution .90*
2. G.P.M. Req’d.
@180°F (82°C), 20°F (11°C) Δt
(no correction to pump curve) 1.10%*
3. Pump Head Req’d. @180°F (82°C)
w/increase in G.P.M. 1.23%*
4. Specify gravity (water = 1.0) 1.045-1.055*
5. Pounds/Gallons @60°F (16°C) 8.77
(water = 8.3453 Pound/Gallon)
6. pH @ 50% by volume 9.5
The performance data listed in Table
6 includes sound ratings. The ratings
provide a guide in determining the
acceptabledegreeofloudnessinparticular
occupancy situations.
Certain general rules apply to specific
selection of unit heaters with regard to
degree of quietness (or loudness);
•
The greater the fan diameter, the
higher the sound level.
• The higher the motor RPM, the higher
the sound level. Note that on most
units the lower the speed mode results
in lowering the sound rating one incre-
ment.
• Selecting a larger number of smaller
units generally results in lower overall
noise levels than fewer large units.
All horizontal steam and hot water unit
heater motors, whether fan guard or
shelf-mounted, are isolated from the
mechanical mount by resilient isolators.
This mounting along with balanced fan
blades and excellent overall construction
integrity, assures you the utmost in quiet
operation.
The following table outlines sound ratings
for various applications. The lower the
number, the quieter the unit and the lower
the sound requirement.
Propylene
Glycol
7. Freezing Point 55% by volume -
50% -28°F (-33°C)
40% -13°F (-25°C)
30% + 4°F (-16°C)
20% +17°F (- 8°C)
*Compared to water.
Altitude Factor
Sea level - 1000 ft.(305m) 1.00
1000 ft.- 3000 ft. (915m) .958
3000 ft.- 5000 ft. (1524m) .929
5000 ft.- 7000 ft. (2134m) .900
7000 ft.- 10000 ft. (3048m) .871
Approximate factors at varying altitudes

10
—
1140
1140
1140
—
5.0/2.5
5.0/2.5
5.0/2.5
—
1/3
1/3
1/3
8.3
12.2
16.7/8.3
21.6/10.8
4.6
6.8
9.3/4.7
12.0/6.0
230/1/60
208-230/460/3/60
1
1.8
1.5
1.8
2.8
5.6
6.8
0.5
1.8
0.8
1.8
2.8
5.6
6.8
3.3-3.3/1.6
18, 24,
108A, 118A
136A
36, 125A
48, 60, 72
84, 96,108
120, 132, 144
156, 180, 204
240
280, 300, 360
18, 24,
108A, 118A
136A
36, 125A
48, 60, 72
84, 96,108
120, 132, 144,
156,180, 204,
240
280, 300, 360
48, 60, 72, 84,
96, 108, 120,
132, 144, 156,
180, 204, 240
280, 300, 360
1550
1000
1550
1000
1000
1140
1100
1550
1000
1550
1000
1000
1140
1100
1140
—
2.2/1.1
2.2/1.1
2.2/1.1
1140
1140
1140
1140
16W*
1/20*
25W*
1/20*
1/12*
1/3
1/2
16W
1/20†
25W
1/20†
1/12†
1/3†
1/2†
1/2**
0.8
1.4
1.2
1.4
2.2
4.5
5.4
0.4
1.4
0.6
1.4
2.2
4.5
5.4
2.6-2.6/1.3
1.8
3.2
2.7
3.2
5.0
10.1
12.2
0.9
3.2
1.4
3.2
5.0
10.1
12.2
5.9-5.9/2.9
MOTOR DATA
NOTE 1: All motors are constant speed and
operate at top speed as indicated in motor data.
Models 18 through 108, including 108A, 118A,
125A and 136A can be run at reduced speed
with addition of optional variable speed switch.
This switch is factory-calibrated for low and high
speed ratings, with intermediate speeds infinitely
controllable. Models 120 through 360 operate at
constant speed as indicated in motor data. All 1/4
H.P.motorsare P.S.C.
NOTE 2: Motors under 1/3 H.P. are totally
enclosed, frame mounted, 115/1/60 with thermal
overload protection and permanently lubricated
sleeve bearings with optional speed controller
available. 1/3 H.P. (115/1/60) motors are open
frame constant speed with thermal over-load
protection and ball bearings. 1/3 H.P. (230V) and
1/2 H.P. (230V) motors are open frame constant
speed with thermal overload protection and ball
bearings.
NOTE 3: 1/3 and 1/2 H.P. motors are available
as 230V single and 3 phase in open frame
and explosion-proof housings, all available
as options. 1/3 and 1/2 H.P. motors operate at
singlespeed only.
NOTE 4: Stated AMP draw is Full Load Amp
(FLA). AMP draw varies by motor manufacturer
±0.2 AMPS.Verify FLAper unitmotordata plate.
Select appropriate AMP,
MCA, and MOP for the multiple voltage
motors. For example, the AMP, MCA,
and MOP for Models 360 with a 460 volt
Totally Enclosed motor is 1.3, 1.6 and 2.9
respectively.
NOTICE: Also refer to Maintenance section for
additional motor data.
Table 11 -TOTALLY ENCLOSED MOTORTYPE
Unit
Model
No.
AMP MCA MOP HP RPM
1/6†
1/4†
1/3***
1/2***
3.7
5.4
7.4/3.7
9.6/4.8
48, 60, 72, 84,
96, 108, 120, 132
144, 156, 180,
204
240, 280, 300
360
115-230/1/60
Table 12 - EXPLOSION PROOF WITH THERMAL OVERLOAD MOTORTYPE
Unit
Model
No. AMP MCA MOP HP RPM AMP MCA MOP HP RPM
—
2.8/1.4
2.8/1.4
2.8/1.4
***These motors are 115/230 volts.
†230/1/60 unit has 115/1/60 motor supplied with field installed stepdown transformer.
*Optional variable speed switch is available.
**These motors are without thermal overload protection.
†230/1/60 unit has 115/1/60 motor supplied with field installed stepdown
transformer.
115/1/60
230/460/3/60

11
LOCATION
It is assumed that the design engineer has selected,
sized, and located in the area to be heated. However,
the information given here may be of additional help to
the installer. These sketches indicate suggested basic
locations for different types of unit heaters.
Horizontal unit heaters should be located to give a
circulatory motion, preferably in the outer perimeter of
the building. The units should be spaced to properly
blanket the areas with warm air.
The unit should be suspended from connections
provided in the unit by means of rods. The rods should
then be attached to solid supports of the building.
Figure 5
Figure 6
MOUNTING HEIGHT AND
APPROX. HEAT THROW
Based on 2 PSI (13.8 kPa) steam pressure
and 60°F (16°C) entering air temperature
A large square area with
exposed walls and roof; units
are blanketing all exposed
surfaces.
A small area with exposed
walls requiring one unit.
A narrow area with two
exposed walls either with or
without roof exposure.
H
MAXIMUM DISTANCE OF THROW =T
Table 13
Typical arrangement of unit heaters in
manufacturing plant, showing air flow
patterns. Not to scale.
8 (2.4)
8 (2.4)
9 (2.7)
9 (2.7)
8 (2.4)
8 (2.4)
9 (2.7)
9 (2.7)
10 (3.0)
10 (3.0)
10 (3.0)
11 (3.4)
11 (3.4)
12 (3.7)
13 (4.0)
13 (4.0)
13 (4.0)
13 (4.0)
13 (4.0)
14 (4.3)
14 (4.3)
15 (4.6)
15 (4.6)
20 (6.1)
25 (7.6)
29 (8.8)
29 (8.8)
20 (6.1)
24 (7.3)
28 (8.5)
30 (9.1)
30 (9.1)
29 (8.8)
30 (9.1)
38 (11.6)
40 (12.2)
40 (12.2)
54 (16.5)
55 (16.8)
55 (16.8)
53 (16.2)
55 (16.8)
57 (17.4)
57 (17.4)
58 (17.7)
60 (18.3)
108A
118A
125A
136A
18
24
36
48
60
72
84
96
108
120
132
144
156
180
204
240
280
300
360
Model
No. Maximum Mounting HT. ft (m) Approx. Max. Throw ft (m)

12
INSTALLATION
UNIT MOUNTING
Install unit heaters to meet Occupational Safety and
Health Act (OSHA) and ETL requirements. Unit heaters
mounted lower than 8 feet (2.4m) from the floor must be
equipped with an OSHA fan guard.
NOTICE: Units equipped with the motor mounted to
the fan guard require two point suspension. Units
equipped with a shelf mounted motor are required to
be suspended at four points. Refer to Figures 3 and
4 for two point suspension and refer to Figure 6A for
four point suspension.
Unit heaters must be hung level
from side to side and from front to back. Failure
to do so will result in poor performance and/or
premature failure of the unit.
Make certain that the lifting
methods used to lift the heater and the method
of suspension used in the field installation of the
heater are capable of uniformly supporting the
weight of the heater at all times. Failure to heed
this warning may result in property damage or
personal injury!
Insure that all hardware used in
the suspension of each unit heater is more than
adequate for the job. Failure to do so may result
in extensive property damage, severe personal
injury, or death!
Make sure that the structure
to which the unit heater is to be mounted is
capable of safely supporting its weight. Under
no circumstances must the water lines or
the electrical conduit be used to support the
heater; or should any other objects (i.e. ladder,
person) lean against the heater water lines or
the electrical conduit for support. Failure to
heed these warnings may result in property
damage, personal injury, or death.
Nutserts are provided at the top of all units for
suspension purposes. Support rods should support
the total unit weight to assure that no strain is placed
on supply and return piping. Provisions for removal of
the unit from the suspension rods may be desirable for
servicing purposes.
Units must hang level vertically and horizontally.
Providesufficientclearancearoundunitsformaintenance
purposes.
Isolators are not required but may be desirable for some
applications. Refer to “Dimensional Data” in Tables 1
and 2.
PIPING
To provide proper coil operation, follow all piping
recommendations listed in this manual.
See Figures 7 through 11 for proper pipe connections.
Follow standard practices and codes when installing
the piping. Provide swing joints for expansion purposes,
unions and shut-off valves for servicing purposes and as
illustrated in Figures 7 through 11, valves and traps for
control purposes. Use 45 degree angle run-offs from all
supply and return mains.
Dirt pockets should be the same pipe size as the return
tapping of the unit heater. Also, pipe size in the branch-
off should be the same size as the tapping in the traps.
Beyond the trap, the return lateral pipe should be
increased one size up to the return main.
It is assumed that the design engineer has selected the
type of system to be used. The sketches shown are for
different types of steam systems or hot water systems.
For sizing of piping, traps, filter, etc., consult ASHRAE
guidesof themanufacturer’s literature onthese products.
It is important that the system be kept clean.Care should
be exercised that excessive joint materials or foreign
substances be kept out of the system.
On steam systems it is recommended that the unit
be installed level for proper condensate drainage.
Swing joints should be used in piping, and pipes should
be pitched down from units so that condensate can
drain freely.

13
Figure 6A
Four Point
Suspension -
Shelf Mounted
Motors Only
"FORCED HOT WATER"
(Serpentine Units)
RETURN
SUPPLY
PET COCK
(SYSTEM VENT)
GATE VALVE
GATE VALVE
DRAIN VALVE D-6057
RETURN
SUPPLY
PET COCK
(SYSTEM VENT)
GATE VALVE
GATE VALVE
DRAIN VALVE
"FORCED HOT WATER"
D-6056
Figure 8
Forced HotWater
Serpentine Unit Only
Figure 7
Forced
HotWater
C
L
C
L
D6340
UNIT SIZE
48/60
72
84 & 120
96/108
132/144/156
180/204
240/280
300/360
A
17-13/16
31-9/16
26-1/16
22-13/16
21-9/16
19-1/16
15-5/16
16-9/16
2-1/2
6" 10"
3-1/2
4"
3"
1-7/8
2-1/2
4-1/2
BC
11-11/16
A
1-3/4
C
1"
B B 1-3/4
C
4 PT. SUSPENSION
USE 3/8-16
THREADED RODS
(4 LOCATIONS)

14
PITCH UP
PITCH UP
RETURN
SUPPLY
PET COCK
GATE VALVE
"HIGH PRESSURE STEAM"
GATE VALVE
BUCKET TRAP
(WITH AIR BYPASS)
STRAINER
D-6058
Figure 9
High Pressure
Steam

15
RETURN
SUPPLY
GATE VALVE
"LOW PRESSURE STEAM GRAVITY"
GATE VALVE
AIR VENT
MIN. SIZE 3/4
CHECK VALVE
PITCH UP
10" MIN. (254 MM)
PITCH UP
D-6059
Figure 10
Low Pressure
Steam Gravity

16
PITCH UP
PITCH UP
RETURN
SUPPLY
GATE VALVE
"LOW PRESSURE
GATE VALVE
F & T TRAP
STRAINER
VAPOR OR VACUUM"
D-6060
Figure 11
Low Pressure
Vapor Or Vacuum

17
HAZARDOUSVOLTAGE!
DISCONNECT ALL ELECTRIC
POWER INCLUDING REMOTE
DISCONNECTS BEFORE
SERVICING. Failure to
disconnect power before
servicing can cause severe
personal injury or death.
Standard units are shipped for use on 115 volt, 60 hertz
single phase electric power. The motor nameplate and
electrical rating on the transformer should be checked
before energizing the unit heater electrical system. All
external wiring must conform to ANSI/NFPA No. 70-
2006, National Electrical Code (or the latest edition) and
applicablecurrent localcodes;inCanada, to theCanadian
Electrical Code, Part 1 CSA Standard C22.1.
Do not use any tools (i.e.
screwdriver, pliers, etc.) across the terminals to
check for power. Use a voltmeter.
It is recommended that the electrical power supply to
each unit heater be provided by a separate, fused and
permanently live electrical circuit. A disconnect switch of
suitable electrical rating for each unit heater should be
located as close to the controls as possible. Each unit
heater must be electrically grounded in accordance with
National Electric Code, ANSI/NFPA No. 70-2006 (or the
latest edition) or CSA Standard C22.1. Sample wiring
connections are depicted in Figures 12 through 22.
OPERATION
Most basic unit heater systems are controlled by a room
thermostat.Locate thermostat oninner wallorcolumn so
that optimum control can be obtained for that area. Set
thermostat for desired temperature.
On steam systems a low limit may be used to prevent
fan from blowing cold air unless the heater has steam
passing through the coil.
Small hot water systems could have the circulating
pump controlled directly by the room thermostat. On
large systems, zone valves could be used to control the
individual unit heater where constant water circulation is
used on the main system.
Horizontal louvers are standard equipment on horizontal
unit heaters, vertical louvers are available as an optional
accessory.
THERMOSTAT WIRING AND LOCATION
NOTICE: The thermostat must be mounted on a
vertical vibration-free surface free from air currents
and in accordance with the furnished instructions.
Mount the thermostat approximately 5 feet (1.5 m) above
the floor in an area where it will be exposed to a free
circulationof averagetemperatureair.Always refer tothe
thermostat instructions aswellas ourunit wiring diagram
and wire accordingly. Avoid mounting the thermostat in
the following locations:
1. Cold areas - Outside walls or areas where drafts
may affect the operation of the control.
2. Hot areas - Areas where the sun’s rays, radiation,
or warm air currents may affect control operation.
3. Dead areas - Areas where air cannot circulate
freely, such as behind doors or in corners.
NOTICE: For all wiring connections, refer to the
wiring diagram on the motor nameplate (also refer to
page 18). Should any original wire supplied with the
heater have to be replaced, it must be replaced with
wiring material having a temperature rating of at least
105° C.
ELECTRICAL CONNECTIONS

18
WIRING INSTALLATION
Figure 12 Figure 13 Figure 14
Figure 15 Figure 16 Figure 17
Figure 18 Figure 19 Figure 20
Figure 21 Figure 22
1 PHASE LINE
MAGNETIC
STARTING SWITCH
THERMOSTAT MOTORS
SPEED
CONTROLLERS
1 PHASE LINE
MOTOR
MANUAL STARTING
SWITCH
ROOM THERMOSTAT
MOTOR
MANUAL STARTING
SWITCH
1 PHASE LINE
3 PHASE LINE
MAGNETIC
STARTING SWITCH
THERMOSTAT
MOTORS
MOTOR
MANUAL STARTING
SWITCH
3 PHASE LINE
MANUAL CONTROLWITH
SINGLE PHASE MOTOR THERMOSTATIC CONTROLWITH MANUAL STARTER
THERMOSTATIC CONTROL USING
MAGNETIC STARTER OPERATING
SEVERAL UNITS
SPEED CONTROLLERWITH
MANUAL STARTING SWITCH SPEED CONTROLLERS WITH
MAGNETIC STARTING SWITCH FOR OPER-
ATING SEVERAL UNITS
MANUAL CONTROLWITH
THREE PHASE MOTOR
THERMOSTATIC CONTROL
OF SEVERALTHREE
PHASE UNITS
1 PHASE LINE
MOTOR
MAGNETIC
STARTING SWITCH
THERMOSTAT
MOTOR
1 PHASE LINE
MOTOR
MANUAL STARTING
SWITCH
THERMOSTAT
SPEED CONTROLLER
THERMOSTATIC CONTROLWITH
REVERSE ACTING CONTROLLER
AND MANUAL STARTER
THREE POSITION SELECTOR SWITCH
USED FOR EITHER MANUAL OR
THERMOSTATIC CONTROL
THREE POSITION SELECTOR SWITCH
BUILT INTO MAGNETIC STARTER FOR
MANUAL ORTHERMOSTATIC CONTROL
THERMOSTATIC CONTROL WITH
LIMIT CONTROLLER FOR
THREE PHASE MOTOR
NOTICE
1. When using a speed controller,
always locate the thermostat
betweenthespeedcontrollerand
the line, not between the motor
and the controller.
2. For internal wiring and over-
load protection on all starters,
consultthecontrol manufacturer
for details.
3. When using thermostatic control
with a manual starter, be sure
that the electrical rating of the
thermostat is sufficient to carry
the motor current.
1 PHASE LINE
MOTOR
MANUAL STARTING
SWITCH
ROOM THERMOSTAT
LIMIT CONTROLLER
REVERSE ACTING
MOTOR
MANUAL STARTING
SWITCH
1 PHASE LINE
LIMIT CONTROLLER
SELECTOR
SWITCH THERMOSTAT
MOTOR
MANUAL STARTER
WITH BUILT IN
SELECTOR SWITCH
1 PHASE LINE
LIMIT CONTROLLER
THERMOSTAT
MOTOR
MANUAL STARTING
SWITCH
3 PHASE LINE
LIMIT CONTROLLER
REVERSE ACTING
THERMOSTAT

19
VARIABLE SPEED CONTROL
115Volt Only (optional)
The solid state speed controller may be installed at any
convenient location and is suitable for surface or flush
type mounting. A Standard electrical single or double
gang wall box is recommended as in Figure 23.
Figure 23
Wiring Diagram of Speed Control Installation
Installation procedure:
1. Attach the control’s leads to the electrical leads in
the control box using wire nuts. The speed control
is to be wired in series with the motor. See wiring
diagram in Figure 23.
2. Make certain wire nuts are tight with no copper wire
being exposed.
3. Place wires and wire nuts back into box allowing
room for the control to fit in box also.
4. Mount speed control to box using number 6
flathead screws provided.
Setting the control:
1. Turn the control shaft fully clockwise. If the motor
is not running at the desired low speed, adjust the
trim on the face of the control for low speed setting
using a small screwdriver.
2. Rotate the control shaft counter clockwise. The
speed will increase smoothly from minimum to
maximum and then switch off.
3. Mount face plate with screw provided and attach
control knob.
STRAP-ONWATER CONTROL
A SPDT strap-on type hot water control with 100° to
240°F (38 to 116°C) rated at 10 amps at 120V is also
available.Control can be used for direct or reverse acting
applications as high or low limit.
STEAM PRESSURE CONTROL
SPDT switch opens on a rise in pressure. Control is
automatically reset, has a range of 0 to 15 PSIG (0
to 103 kPa) and has an adjustable differential. Other
actions, ranges, circuits and manual reset models
are available on request.
OPTIONS
HORIZONTAL AND VERTICAL LOUVERS
Horizontal louvers are standard on all models. Vertical
louvers are an optional accessory on all models.Vertical
louvers are installed on built to order units or shipped
loose for field installation.
Figure 24
Horizontal andVertical Louver Mounting
THERMOSTATS
Line voltage wall thermostats are in stock for immediate
shipment.AllmodelsareSPSTwithbimetalthermometer,
knob-type set point adjustment, 40 to 90°F (5 to 30°C)
range and selector switches.Standard duty models with
“off-auto” and “auto-off-fan” and a heavy duty model
with “auto-off-fan” switching are available. Other models
available on request.Plastic tamperproof one size fits all
thermostat guards are also available.
MANUAL STARTERS
Single and three-phase models are available. Standard
models are single-speed, toggle-operated, NEMA Type
1 and are surface-mounted.
WALL MOUNTED SPEED CONTROLLERS
Units with standard motors up to Model 108 (115/1/60)
can be operated at reduced speeds by addition of
optional speed controller. Controller is 5 amps, pre-set
at factory for maximum and minimum speeds, with
intermediate speeds infinitely controllable. All 1/3, 1/2
HP and 230V motors operate only at rated speed and
CFM – See Charts.
NOTICE: When using electrical accessories, always
refer to the accessory manufacturer’s installation
manual for proper use, location and wiring
instructions.

20
MAINTENANCE
PERIODIC SERVICE
Open all disconnect switches and
secure in that position before servicing unit. Failure
to do so may result in personal injury or death from
electrical shock.
Because of the simple design of the steam and hot
water unit heaters, they are nearly maintenance free.
However, depending on the environment, simple
maintenance practices should be adopted.
Periodically check the finned surfaces and vacuum
these as often as necessary to remove any
accumulation of lint and dirt. Check fan blades and
remove dirt accumulation. If fan blades are not cleaned
they tend to become unbalanced.
Most of the motors supplied on the unit heaters have
either ball bearings or sleeve bearings and should not
require lubrication for long periods of time. It is however
advisable that motor maintenance and lubrication
recommended by the motor manufacturer be followed.
Check motors for dirt and dust accumulation, and
remove any accumulation as often as necessary. Open
type motors may overheat if the dirt or dust is not
removed from ventilation openings.
Allow rotating fans to stop
before servicing to avoid serious injury to
fingers and hands.
MOTOR LUBRICATION
Sleeve Bearings
Motors with oilers or oil holes are lubricated before
shipment with a good grade of electric motor oil. Refill
when necessary, with the motor at a stand-still, until oil
reaches the proper level.
Use SAE 20W non detergent oil for motors operating
in ambient temperatures of 32°F to 100°F (0°C to
38°C). Below 32°F (0°C), SAE 10W non detergent oil
will be required.
The frequency of oiling will depend upon operating
conditions and length of running time. Inspect the oilers
or oil holes when cleaning the unit. If the unit has a
fractional horse-power motor, lubricate at least once
a year. Under high ambient conditions or constant fan
operation, fractional horse-power motors should be
lubricated every 90 days. On those motors without
oilers or oil holes, follow the instructions given on the
motor nameplate.
Ball Bearings
Ball bearing motors are pre-lubricated and normally
not equipped with grease fittings. However, motors
are equipped with removable grease plugs to allow
installation of grease fittings if desired by owner. Motor
manufacturers do not recommend or require on the job
lubrication of ball bearing motors.
If on the job lubrication is required by the owner, use
the following procedure: With the motor at a stand-still,
remove the vent and grease plugs. Install grease fitting
and add grease sparingly. Remove the old grease
from the vent relief chamber. Operate the motor a
few minutes before reinstalling the vent plug to allow
excess grease to escape. If there is evidence of grease
working out around the motor shaft, less grease should
be added and the greasing periods lengthened. If
grease continues to appear, take the motor to the motor
manufacturer’s authorized service station for repair.
NOTICE: Consult local motor manufacturer’s
service facility for information on type of grease
and oil to be used.
NOTICE:The heater system should be checked once
a year by a qualified technician. All maintenance/
service information should be recorded accordingly
on the inspection sheet provided in this manual.
Should maintenance be required, perform the following
inspection and service routine:
CLEANINGTHE UNIT
The unit casing, fan, diffuser and coil should be
cleaned thoroughly once a year. Coil heat transfer
efficiency depends on cleanliness. The following
recommended procedures may be performed when
lubricating the motor and cleaning the coil.
1. Wipe all excess lubricant from the motor, fan and
casing. Clean the motor thoroughly. A dirty motor
will run hot and eventually cause internal damage.
2. Clean the coil:
a) Loosen the dirt with a brush on the fan side of
the coil. Operate the motor allowing the fan to
blow the loosened dirt through the unit.
b) Use high pressure air or steam on the side of
the coil away from the fan.
NOTICE: A piece of cheesecloth or a burlap bag
may be used to collect the large particles during
the cleaning process.
3. Clean the casing, fan blades, fan guard and
diffuser using a damp cloth. Any rust spots on the
casing should be cleaned and repainted.
4. Tighten the fan guard, motor frame and fan bolts.
Check the fan for clearance in the panel orifice and
free rotation.