Lennox ECB21-12.5-1P, ECB21 Series, ECB21-20.0-1P, ECB21-25.0-1P, ECB21-30.0-1P Installation Instructions Manual

Supersedes 502,704M

ELECTRIC UNITS ECB21 SERIES HEATERS

INSTALLATION INSTRUCTIONS FOR ECB21 SERIES ELECTRIC

HEAT SECTIONS USED IN B21/CB21/CBH21 APPLICATIONS

503,018M
9/93

I--SHIPPING AND PACKING LIST
Package 1 of I contains:

1-- Assembled electric heat section
1- - Filler plate for use with:

ECB21- -5.0- -1P,ECB21- -6.0- -1P,
ECB21- -7.0- -1P,ECB21--8.0- -1P,
ECB21- -10.0- -1P, ECB21- -20.0- -1P

2-- Wiring diagram stickers

II--SHIPPING DAMAGE

Check heater forshipping damage. The receiving party
should contact the last carrier immediately ifany dam-
age is found.

Ill--GENERAL

These instructions are intended as a general guide

and do not supersede local or national codes in any
way. Authorities having jurisdiction should be con-

sulted before installation.
IV--REQUIREMENTS

Installation of Lennox blower coil units with electric heat
must conform with standards in National Fire Protection

Association (NFPA) "Standard for Installation of Air
Conditioning and Ventilating Systems NFPA No. 90A,"
"Standard for the Installation of Residence- -Type Warm

Air Heating and Air Conditioning Systems NFPA No.
90B," manufacturer's installation instructions and local
municipal building codes.

This unit is approved for installation clearances to com-
bustible materials as listed on the unit heater installed

nameplate located on the blower coil unit. Accessibility
and service clearances must take precedence over

combustible material clearances.

,& WARNING

V- -APPLICATION

ECB21 series heaters are designed to provide field
installed electric heat for B21 blower units and CB21

and CBH21 series blower coil units.

_]_rat Ical _1993 Lennox Industires Inc.

ure Page 1

VI--INSTALLATION

NOTE--If replacing an existing electric heat section, dis-
connect and remove the existing heat section and wiring.

1- - Disconnect power to B21!CB21/CBH21 unit.
2-- Remove blower access panel.

3-- Remove circuit breaker knockout on blower/blow-

er coil access cover in applications using an
ECB21 12.5, 15.0, 20.0, 25.0 or 30.0--Y, --P volt-

age heater in a CB/CBH21--41 or B/CB21--51/65
unit (See figure 1).

KNOCKOUTS IN B/CB/CBH21 UNIT

ACCESS PANEL

I

CB/CBH21--41

REMOVE LARGER KNOCKOUT FOR USE WITH

ECB21-q5.0--1Y HEATER; REMOVE BOTH KNOCKOUTS

IF ECB21--12.5/15.0/20.0--1P HEATERS ARE USED.

B/CB21 - -51/65

4-- Remove blank filler plate(s) in control box.
5-- Adjust circuit breaker mounting bracket according

to B21/CB21/CBH21 application. Bracket adjusts
forward by removing mounting screws, reposition-
ing bracket and reinserting screws (See figure 2).

6- - Slide ECB21 heat section into opening. Hole(s) on

each side of ECB21 line up with holes in control
box (See figure 3). Reinstall screws to secure heat

assembly. On the following ECB21 heaters, circuit
breakers line up with the opening in the access

cover: ECB21 12.5, 15.0, 20.0, 25.0 and 30.0 kwY
and P voltage heaters.

7- - When installing 5.0, 6.0, 7.0, 8.0, 10.0 and 20.0 kw

P voltage heaters; 5.0, 7.5, 10.0 and 15.0 kw Y volt-
age heaters in CB/CBH21--41 or B/CB21--51/65
units, a filler plate(s) (provided) must be used to

seal the element opening (See figures 3 and 4).

FILLER PLATE

VESTIBULE PANEL

ECB21--15.0--1Y HEATER IS USED.

REMOVE ALL THREE KNOCKOUTS IF ECB21- -25.0/30.0- -1P

OR ECB21--20.0/25.0--1Y HEATERS ARE USED.

FIGURE 1

ECB21 IN CB/CBH21--41

CIRCUIT BREAKER POSITION

ECB21 IN B/CB21--51/65

CIRCUIT BREAKER POSITION

ECB21 ELEMENT _.j

ASSEMBLY

UPPER
FILLER

PLATE\

I

I

f

OPENING

IN 51/65

_L

I

FIGURE 3

FILLER

PLATE

\

ECB21 ELEMENT

FACE PLATE

OPENING

21/26/31/41

VESTIBULE

PANEL

UPPER
FILLER

IN

Page 2

ECB21* q5.0**lP

FACEPLATE

FIGURE 4

BLOWER

DECK

VII--FIELD WIRING CONNECTIONS

Refer to field wiring diagrams on pages 5 through 13.

IMPORTANT--On the units listed below, field power
supply wiring must be connected to the circuit breakers
and NOT the line voltage terminal block.

ECB21- -12.5- -1P ECB21- -15.0- -1Y
ECB21- -!5.0- -1P ECB21- -20.0- -1Y
ECB21- -20.0- -1P ECB21- -25.0- -1Y
ECB21- -25.0- -1P

ECB21- -30.O--1P

Power wiring for all other ECB21 heaters installed in B/CB/
CBH21 blower coil units should be connected as follows:

1- - Connect black power wire(s) marked "L1 "to L1 ter-

minal of TB2 terminal block.

2-- Connect red power wire(s) marked "L2" to L2 ter-

minal of TB2 terminal block.

NOTE- -All power wires on three- -phase heaters are
black.

3--Three--Phase Heaters Only .... Connect black

power wire(s) marked "L3" from ECB21 heater to
L3 terminal on TB2 terminal block.

4-- Heaters are supplied with an interconnecting jack

plug attached to each assembly. Connect the plug
from the heater to the matching plug inside the
blower coil unit.

5-- Heaters may be used with thermostats which con-

tain a second--stage heat bulb or with an outdoor
thermostat.

If indoor thermostat contains a second--stage
heat bulb, disconnect wire labeled "W2" from ter-
minal "R" ofTB1 terminal block and connect wire to

second--stage heat bulb.
If an outdoor thermostat is used, connect wire la-

beled "W2" to the outdoor thermostat. Refer to the

unit wiring diagram.
6-- Replace blower compartment access cover.
7-- Two ECB21 wiring diagrams have been included

with the heater. Affix one diagram on the

CB21/CBH21 unit next to the unit wiring diagram.

Affix the second wiring diagram in the outdoor unit

near the CB21 wiring diagram.

NO TE- -Refer to blower coil unit namepla te for mini-
mum circuit ampacity and maximum overcurrent
protection size.

VIII--COMPLETE INSTALLATION
Refer to CBiCBH21 installation instructions for com-

plete plumbing and drain connections, as well as duct
system installation.

IX--BLOWER MOTOR SPEEDS
A--Air Volume Adjustment

CB21 and CBH21 units are equipped with a variable
speed motor that is capable of maintaining a specified
CFM throughout the external static range. Select 1 of 11
speed taps located behind the tap cover on the motor/
controller to obtain a particular CFM. See figure 6 for tap
cover, AC power and control interface plug locations.
Refer to figure 7 for speed taps, high speed, low speed
and heat speed connectors. Refer to table 1 for mini-

mum blower speed tap for heating.

TABLE 1

MINIMUM BLOWER SPEED TAP,'

HEAT

PUMP

HP21- -411

HP21* -511

HP21* -651

BLOWER

COIL

CB21- -41- -1P

CBH21- -41- -1P

CB21- -51- -1P

B21/CH21- -51- -1P

CB21- -65- -1P

B21/CH 19- -65- -1P

ELECTRIC

HEAT ONL_

FOR HEATING

HEAl"

PUMP

ONLY

8

8

8

HEAT

PUMP

WITH

ELEC.

HEAT

6 8
6 8

7 9

The B21--51/65 is factory wired for CH19--65 ap-
plications and must be field wired for CH21 --51 ap-
plications.

B--Blower Speed Adjustment Procedure
Use the following procedure to change blower speed
selection for high, low or heat speed selection:

, WARNING

1-- Disconnect line voltage from unit.
2-- Disconnect AC power plug from motor/controller.

See figure 6.

3-- Slide the tap cover toward AC power connection.

See figure 6.

4--Remove the appropriate speed connector and

place it on the proper tap. See figure 7.

Page 3

5--Whenallspeedconnectionsaremadetoproper

taps,closetap coverand reconnectACpower

plugtomotor!controller.
6--Reconnectlinevoltagetounit.

o %oo .o%OR°-

E

Io o-

FIGURE 6

LOW- -

WHITE CONNECTOR _ HEAT--RED CONNECTOR

HIGH--BLACK CONNECTOR TAP #1

TYPICAL VIEW--PINS NOT IN ANY ORDER

FIGURE 7

X--POWER WIRING CONNECTIONS
Refer to nameplate on blower coil unit for minimum circuit

ampacity and maximum overcurrent protection size. If
single point power supply is desired, refer to nameplate

on single point power supply accessory or see table 2

for minimum circuit ampacity and maximum overcur-

rent protection size. Select the proper supply circuit

CONTROL

INTERFACE

PLUG

= = I"

conductors in accordance with tables 310--16 and
310--17 in the National Electric Code, ANSl/NFPA No.
70 or tables 1 through 4 in the Canadian Electric Code,

Part I, CSA Standard C22.1.

TABLE 2

MINIMUM CIRCUIT AMPAClTY & MAXIMUM

OVERCURRENT PROTECTION SIZES FOR

SINGLE POINT POWER SUPPLY APPLICATIONS

CB/CBH21- -41 B21- -51/65

ECB21

Elelctric Minimum Maximum Minimum Maximum

Heat Cirucit Overcurrent Cirucit Overcurrent

Ampacity Protection Ampacity Protection
208/240V 208/240V 208/240V 208/240V

--12.5--P 64/72 70/80 68/77 70/80

- -15.0- -P 75/85 80/90 79/90 80/90

--20.0--P 97/11t 110/125 101/116 110/125

- -20 O- -Y - - 1 .... / - - 63/72 70/80

- -25.0- -P -- / .... /-- 124/142 125/150

- -25.0- -Y - - / .... 1- - 77/87 80/90

- -30.0- -P -- / .... /-- 146/168 150/175

The blower coil units are provided with knockouts for
use with 1- -1/2 inch trade size (1- -31/32 inch diameter)

conduit. A conduit mounting plate has been pro-
vided for use if installing smaller conduit.

XI--FIELB WIRING

Figure 8 and 9 respectively show typical heat pump
and condensing thermostat wiring when electric heat is
used,. Refer to figures on the following pages for field
wiring of electric heat elements in blower coil units.

NOTE--When installing CB21/CBH21 unit with or with-
out "Efficiency Plus" CCB1 (A20), or with matches other
than HP21, jumper wires maybe needed for proper op-
eration. Refer to tables and notes in figures 8--16 for

proper application of jumper wire.

CAUTION--Incorrect placement of jumper wire on
TB1 terminal board will reslut in damage to CCB1

control.

Page 4

HEAT PUMP WITH ELECTRIC HEAT

Z__ EM HT RELAY

_ _ K22

r- --r'-z'-./i1

CLASS2 VOLTAGE FIELD INSTALLED
NEC/CEC

NOTE-ALL REMAINING WIRES
FACTORY INSTALLED

S23 OUTDOOR

THERMOSTAT I-Y-_ II s, THERMOSTAT z_

(IF USED) _ _

TBI -- -- -- ;q _(_ _v._ 1

( I '

ot;t to'ot ,- -,,,,,,,,,,-_,k_,,,__+_,,

I_)L)_( ..(.r)(,,2q (,-)(.,.).P,.,d _ '

:rilr.lt:lr 1. :/"_", rL'-d':_I_--- _ ! I i i I '

I I I I i"1","C-_i_.;:_1",'1_= _'_" - I I I

,ll ; _- "z"_ -_";'- -- -1'- -- -"- -"--'1"--1

I II I' ' ,-_.,.,___--q.,I .--, i ' . •

I it -I .... _ .... ,,-",.-- -- .--"--',',-.J I ,

i,,,._._,,____.,_____.,___ j I I I

] I I'L,I,_..,I,,.,,,_--..,I,----.., .... _,l,_ J _,,_ n I .

. iI.,,...,,,I,,I,_ ....,,.____.,. ..... ,,__ __ ._,I,_._,_ .__,,_ J

_-I,--4,--,I,,,',.- -"1"--- ----.,I'- -- -- -- -...,i'- -- -" ,--"'1"- -...'1'--n

I I I IL --,_.L- _ I I I

I _-J L /

"1__ i CCBI-I UUIY; IYII ;J U U J J

I F;_ll'JJ'_-_ll-_'IF_T]F'_"IF'_-llTERMINAL BLOCK _ _ _--

'_JUL_J_JL._JL_JL_JL._J _ _I z

z_ THERMOSTAT HEAT ANTICIPATION 0 _I _I

SETTING .'€AMP (ELECTRIC HEAT) _ ,o,Io,I

Z_ WHEN TWO STAGE THERMOSTAT IS USED, _: _1 61

cONNECT SECOND STAGE HEAT BULB TO _-I_<1

TERMINAL W2, RB_IOVE.JUMPERBETWEEN _

TERMINALS"R"AND

/_ IHENOUTDOORTHERMOSTATIS USED, . q q

CONNECT LEADS TO TERMINALS "R AND W2," _1 _1

RE_VEJUMPERBETWEEN"R"AND"_" al OI

Z_ EMERGENCYHEATRELAY(USEDONLYIF _l _l

OUTDOOR THERMOSTAT IS USED] FIELD I >I
PROVIDED AND INSTALLED NEAR INDOOR

UNIT Z&VAC BVA MAX NEC CLASS 2

Z_ NEC/CEC CLASS 2 3VA HEAT PUMP CLASS 2

Z_ VOLTAGE TERMINALS

FIELD INSTALLED JUMPERS REQUIRED

FOR TERMINAL STRIP TB1

Humidity

Control

With COB1

Humidity

Control

Without CCBt

Humidity

Control

Outdoor Unit

Single-Speed Heat Pump
Two-Speed Heat Pump

Single-Speed Heat Pump
Two-Speed Heat Pump

Jumpers

Required

Y1 to Y2

none

DS to Y1
DS to Y2

Z_ FACTORY INTSALLED JUMPERS
Z_ COMMON TERMONAL "C" LABELD

"X" ON EARLY NODELS CCB1 - -1.

FIGURE 8

Page 5